I live in Canada and my house is made of wood. I'd like to mount gymnastics rings to my ceiling. I weigh roughly 90kg and I know you're suppose to find joists and attach weight there, but I don't want to pull my ceiling down. Is there a way to test or tell if my ceiling will take my weight? Especially since it's dynamic as I will likely be swinging.
It's impossible to say with any confidence without knowing the details of your house's construction.
If there is a regular room above (not an attic) the ceiling you want to hang the rings from, normally those ceiling joists above are also the floor joists of the room above. If it was constructed to modern guidelines those are going to be pretty strong - if you hang the rings from two parallel joists so the load is spread across two joists, and your attachment is sound and solid, that should be strong enough to hold you. After all, it would hold you if you went upstairs, stood over the rings, and jumped up and down.
However it may very well cause enough movement to damage the ceiling drywall, make the floor squeaky, etc., especially if you made a habit of it. If you were jumping up and down on the floor above, the subfloor and floor would help spread the load. With rings, the forces generated by your weight and motion are focused on a single point and may cause the joists to flex more than intended.
If your attachment is not solid, that's a whole different story. For example if you anchor your eye bolts into strapping rather than joists, that will either rip down the ceiling, rip out the eye bolts, or both. If you find a joist but hit it off center and crooked, the eye bolt will look fine from below but will be hanging by a little sliver of wood and will rip out under load. If you're upside down on the rings when that happens, it will be ugly.
How tall are your ceilings?
You're going to be putting huge stresses on the ceiling when you're swinging, even doing simple giants, to say nothing of any sort of move that has a "landing" - all that "jerk" you feel in your shoulders is being transmitted right up to the framing. As a former gymnastics dad, I've watched the rings rig as it moves and wobbles under the weight of even a 10-year-old boy - I can't imagine the forces a college-age or older adult is putting on it.
Having the rings mounted close to the wall would minimize the stress on the joist and maximize the amount it could transmit into the supporting wall. However, that makes swinging a tad difficult (or painful). Therefore, you'd need to put the mounts at least a couple of meters from the wall to have room to swing which puts the stress close to the center of the joist, maximizing the deflection imparted to the joists and maximizing the chances of over-stressing them, leading to cracks and failure.
If all you're going to do is pull up to handstands or crosses, and you're not going to do any swinging, you might get away with mounting the rings a meter or so from the wall to have clearance for your body. Those moves are supposed to be very smooth with a minimum of swing and no jerking. If you intend to do any swinging, remember there's a reason the rig at the gym is made of steel, stabilized with guy-wires, and bolted to concrete (or weighted down with 100s of kilos of weight at each corner for a temporary set up).
Provided you do find joists and not mere ceiling laths, there are two main ways to provide extra strength.
Have a sturdy cross-brace that connects to a number of joists, not just one.
Have vertical supports either side of the rings.
In effect, if you have both of these, you will be building a floor-to-ceiling door-frame with the rings in between. This should be at right-angles to the joists.
Note that, with a little thought, you could make most of the frame removable when necessary.
What kind of swinging? Incidental swinging or purposeful swinging? I could be mistaken, but I don't know of any gymnastic ring exercise where you purposefully swing since I'm pretty sure that's considered bad form.
At 90kg, even if you aren't swinging I would get metal bar mounts intended for gymnastic rings and mount it such that it spreads the weight across multiple joints. And only on the basement joists which support the floor above. Maybe you would be better off buying a heavy power cage and mounting the rings on there, and bolt that to the floor since you're swinging.
I don't swing and am only 60kg. I use a metal mounting bar on my basement ceiling spread across two joists (was supposed to be three but the third bolt got overtorqued and broke in the joist) and even I would not be comfortable swinging.
Why rings? Most ring exercises require some height, and in general you need the full height of your body including arms and toes above and below. Most people don't have 18' ceilings.
If you mostly want to do pull-ups and grip strength exercises, I suggest buying a climber's fingerboard instead. That will have varying grades of hold, at all kinds of distance between, to work on different muscle groups.
If you really want to do rings, the easiest solution is to move outdoors. If you have a 2-storey brick house, you could bolt two cantilevered hanging points securely to the wall. Otherwise consider a freestanding structure with posts set in concrete.
If you're indoors, as other answers have said, a single joist is not designed to take that much point force. The correct solution is usually to run two bars across the joists to spread the load, and attach your hanging points to the centres of those bars. You could likely use a civil engineer (not a builder!) to advise on this.
For permanently installed rigs like this, don't forget that there must be no single point of failure. The ropes to the rings should have thin steel backup lines; and the attachment point at the top should have backup lines to (ideally) two other locations to the side, not in a straight line. This is all pretty well standardized for how heavy loads are suspended. As good as your kit may be, the point is that anything could break (manufacturing defects happen, as do stresses and wear) and falling objects (you!) need to be prevented from falling all the way to the ground. I strongly suggest looking up how climbing walls set up their hang points, and how large stage shows hang loudspeakers and lights.