Someone named Tran? If so, disregard the following:

I assumed you were talking about “the rights of trans folks”, which is usually “trans rights”. In that case, “trans” is an adjective. Like “human” in “human rights”.

If you did want it to be possessive for trans folks, similar to if you said “humans’ rights”, you’d say “trans folks’ rights”.

Because while “human” can be an adjective or a noun, “trans” is only an adjective. So you can call someone “a human”, but not “a trans”.