Hello,
1) There's no reason why you should give up your three month's salary that is overdue especially as you have completed all requisite formalities for resignation from the company. It is immaterial if others are not paid their salaries.
2) Issue a legal notice to the company demanding the arrears of the salary to be paid with interest. Of the company fails to comply you can proceed with a suit for recovery against the company on a civil court.
3) Engage a lawyer locally at your earliest to take the steps on your behalf.