One director involved in criminal activities

You have not clarified, out of the two persons, who has 70% share and who the remaining 30% share in the company.

In the absence of full details, generally speaking, you may face problems since it is a company with only two shareholders and you are supposed to know about its activities. But, in case, you have never conducted the business of the company, never signed any documents, cheques, forms, etc., you can try to show all these aspects to the investigating officer saying that you were holding non-executive capacity and have never actually conducted any transactions. In some of such cases, the police can even make such a person an approver if you tell the full correct details.

If the FIR is already registered and is under investigation, and if the transactions of Ponzi scheme are done in the name of the company, it may perhaps be advisable to obtain anticipatory bail, though for getting a  more a proper and well-informed advice I think you should contact some advocate and show all the relevant papers and discuss all the relevant facts with him.