my father purchase a land on 1984, @56000/- he sold the property on 18-10-2012@1900000/- , and on 31-03-2013 he invest the entire amount plus 10000, that is rs. 19,10,000/- in rec 54ec bond. now my question is : is there any tax liabilities in the hands of my father ? his age is 64 yrs, he has only rental income rs. 100000/-p.a , and another question is it compulsory to submit income tax return for this year ? as his income not exceeds taxable limits so he does not file incometax return since 2000. please advice