he would've got more than one email from his uni warning him of missing lectures long before he went back to India on holiday. my school calculates attendance every two weeks. they do this because international students need to maintain an 80 percent attendance or excused absences in order to keep their visa. this is to prevent immigration fraud, so people don't sneak in on a student visa with no intention of being a student.
the fact that he ignored the warnings and now wants to claim ignorance and mental health probably isn't good. if there is a right to appeal tho i imagine it's on the decision letter.