Gap in itr returns

Dear Sir/Madm, My Friend has filled last itr on AY 2011-12 but this itr is rejected due to no signature on it. after that he is not filling itr till now. In FY 2011-12 he sale his own flat on Rs.1 cr & Give money to his brother in law for recover the loss of his brother in law In the same year he invest some money in Shares What should he do can he compulsory file old ITR Returns or he can file only last two years ITR Please help