return filing

Usually time limit is mentioned in notice 142(1) for filling of return and you have to file return within period specified in notice. You cannot file such return after such period without AO permission.
As you have not filed ITR in response of notice u/s 142(1), it would be better not to file it now.Otherwise following consequences may have to face.

Best Judgement Assessment u/s 144, or

Penalised under Sec 271(1)(b) i.e. Rs10,000 for each failure, or

Prosecution under Sec 276D which may extend upto 1 year with or without fine.