It depends on the rules of your State Government. There is no such Act which says that the suspension shall be revoked automatically if the charge sheet is not served within 3 months. However, last year, the Supreme Court has ruled so in a judgment; read the following article for more details:
Suspension order not to extend beyond 3 months if charge-sheet is not served, says Supreme Court
Also, recently, the Central Government has issued similar instructions (which are applicable to Central Government servants); please read the following article:
Suspension not to exceed 3 months if charge sheet not served, says Central Government
In your case, you have mentioned that you have been convicted in a criminal case. In the Central Government rules and the rules of most State Governments, there is a provision that following conviction in a criminal case, a Government servant can be punished (including dismissal, wherever desirable) on the basis of the conduct that led to the conviction, without even conducting a departmental inquiry. It is pertinent to mention that even if you have filed an appeal against such conviction and even if the sentence has been stayed (or even if the order of conviction itself has been stayed), generally there may not be bar to punish such government servant without holding departmental inquiry in such a case, since the Supreme Court has ruled that in such circumstances, the departmental punishment is based NOT on conviction, but on the CONDUCT that led to the conviction.
Dr. Ashok Dhamija is a New Delhi based Supreme Court Advocate and author of law books. Read more about him by clicking here. List of his Forum Replies. List of his other articles. List of his Quora Answers. List of his YouTube Videos.