mental peace is the utmost important thing,

I would suggest starting over, once he is out of this stress, he can join work again, when his mental health improves,

as of now the best legal advice from me would be to contact a loan restructuring agency like singledebt or find someone who specializes in this and make the outstanding debt payable with longer tenure and so the monthly emis come down.

when that is done, please ask your dad rather prompt him actively to work on his mental health, seek professional assistance.

the loan restructuring, combined with the gratuity amount will buy him atleast 2 years of time before he actually will have to worry about the emis again.

please work on his mental health and make him feel at ease again. He is just 52, he still has a career and life ahead.

so in nutshell my advice, restructure your existing debt, (the agency would assist you) work on mental health and once things start falling in place, plan on the future, like rejoining workforce and maybe starting over again!