Income tax for non resident

One of my Uncle who is Non Resident is having income from Salary/Pension from Central University in Hyderabad.  What is the taxability of this income.

In the above case, he has some savings to him every year.  Based on that savings can he file nil return.  (Please assume that after exemptions u/s 80C the total income will be less than taxable income).  Can he eligible for exemptions for u/s 80C as he is a non resident?

Thanks,

M.Sreenivasa Rao.