Case filed in another state is it necessary to appear in that state?

What I understand is that there is a case of cheating pending in Patna against you. You must have received summons from the court. Yes, in a criminal case you are bound to appear before the magistrate unless your lawyer in Patna is able to move an exemption application on your behalf and get it allowed. You need to appear on the summons from the respective court,. Non-appearance can also lead to issuance of warrants. however, later you may seek permanent exemption or exemption. But granting exemption is discretion of the court. Your local lawyer in Patna will be able to advise you about exemption if you ask him.

Yes, if the matter is filed in Patna, then you will have to travel to Patna if court serves you a notice.
Since, it is a criminal case, so you will have to be present on every date. However few times you can move an application of exemption citing appropriate reasons.