I have been given 2 translations for the sentence

"You can't teach someone who doesn't want to learn, and you can't stop someone who does"

I'm not sure which one to use

1. Ní féidir rud a mhúineadh do dhuine mura bhfuil fonn orthu, ach ní féidir duine a stopadh má tá fonn orthu é a fhoghlaim.

2. Is deachair ceacht a mhúnadh don té nach bhfuil fonn foghlama air,ach ní féidhir cosc a cur leis an té go bhfuil fonn foghlama air.

I would welcome suggestions

Both are correct, but I would tweet it a little bit.

1. Ní féidir rud a mhúineadh do dhuine mura bhfuil fonn air, ach ní féidir duine a stopadh má tá fonn air é a fhoghlaim. (é a fhoghlaim = learn it)
air - because "duine" is singular, so pronoun is singular.

2. Is deacair ceacht a mhúnadh don té nach bhfuil fonn foghlama air, ach ní féidir cosc a cur ar an té a bhfuil fonn foghlama air.

Wait for confirmation, spelling corrections, or better alternatives.

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It is recommended that you always wait for three to agree on a translation.
I speak Connemara Irish, and my input will often reflect that.
I will do an mp3 file on request for short translations.
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spelling corrections (I can only correct you on spelling anyway ):
Is deacair ceacht a mhúineadh don té nach bhfuil fonn foghlama air, ach ní féidir cosc a chur ar an té a bhfuil fonn foghlama air.

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Is fearr Gaeilg na Gaeltaċta ná Gaeilg ar biṫ eile
Agus is í Gaeilg Ġaoṫ Doḃair is binne

GRMA a Lughaidh. Stupid of me to miss those.

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It is recommended that you always wait for three to agree on a translation.
I speak Connemara Irish, and my input will often reflect that.
I will do an mp3 file on request for short translations.
___________________________________________________________

The two ways of expressing it do both work, but are phrased a bit differently. Here's more or less what they mean, with the words in brackets being either alternate choices or words which are there in one language but not in the other (though possibly implied):

Ní féidir rud a mhúineadh do dhuine mura bhfuil fonn air, ach ní féidir duine a stopadh má tá fonn air é a fhoghlaim.
[One] can't teach anything to [someone/a person] if he doesn't have the desire, but you can't stop [anyone/a person] if he has the desire to learn [it].

Is deacair ceacht a mhúineadh don té nach bhfuil fonn foghlama air, ach ní féidir cosc a chur ar an té a bhfuil fonn foghlama air.
It's difficult to teach a lesson to one who doesn't have the desire, but you can't [restrain/hold back] one who has the desire.

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I'm not a native (or entirely fluent) speaker, so be sure to wait for confirmations/corrections, especially for tattoos.