Whoa, a blast from the past!
The key is in the lens name. If it has an 'ef' or 'ef-s' it is compatible with any new Rebel I.E. T6i, T5i, T3. Your T50 on the other have uses 'fd' lenses. They can be made to work but it is difficult and the results are not very good. Stick with ef or ef-s for a new Rebel.