Hi Sinem. 'Tough' is the right word to use with meat. Someone might say the meat is hard as part of a metaphor, e.g. This meat is as hard as nails, but a more common metaphor would still use the word tough - This meat is as tough as leather.
Do you know which word is the opposite of tough when talking about meat?
https://www.italki.com/ana.nz –English and Portuguese Teacher - professora de inglês e português