Tattoo translation help

I want to get a tattoo that says have mercy on me in japanese but i don’t know if it’s the right translation so can someone check if this is correct私に慈悲を?

Yes, that is a correct translation. And a correct translation is not always the same thing as an appropriate phrase, moreover an appropriate font. If a correct translation is all people need, the world would need no human translators.

Questions about tattoo translations come up fairly often on this forum. Typically, the person asking for a translation doesn’t speak Japanese or understand Japanese culture, and people who do speak Japanese and understand Japanese culture try (with varying levels of kindness) to explain why the tattoo in question just seems dumb from their point of view. I sort of enjoy reading these threads just to see the responses.

Obviously, you don’t need to conform to the norms of Japanese culture, and you get to make your own decisions about body art, but you might want to read through a few of these threads on tattoo translations. The most recent one is here:
https://www.japan-guide.com/forum/quereadisplay.html?0+178512

If you click on the link that opens up all the questions on the topic of language and browse the titles, you will find more threads on this subject. The proposed tattoo texts are always different, but the answers are generally pretty consistent and probably not what you want to hear. If you read a half dozen or so of these threads, you might possibly get a different perspective on the idea of tattooing yourself with some Japanese word or phrase that is a translation of an idea that you find meaningful or cool.

I want to get a tattoo that says have mercy on me in japanese

I recommend you don't choose such a thing for your tattoo.

It sounds to me (a Japanese resident)
not common here in Japan
to say "have mercy on me" explicitly on your body,
by tattoo, T-shirt printing, etc.,
unless you are a street performer, a stage comedian or the like.