Nil return justified or not

Yes, definitely....

SIr 

I can't understand, there will be problem or not, because IT will never ask me for the income of source after that?

Based on the financial statements submitted by bank, a query may be raised by department.

Banks maybe filing AIR (Annual Information Return) and submit it to Income Tax department. Certain PAN criteria that fulfill those PAN may reflect in AIR.

There were  opening balance of Rs. almost 4,00,000/-, in the bank so there will be problem?

As long as there was a sufficient amount of opening balance in bank & cash there would be no problem. 

And also as long as the total of credit entries in the bank statement doesnot exceed Rs. 10 lakhs, the probability of case being picked up is less. 

This is my personal opinion.