I have a client who owes me a lot of money, he has given me checks but keeps telling me to hold off on depositing them, he is in Ca, I am in NY, what are my options

Sorry to say this but the only way you are going to be able to go after him is if you tried to cash them and they were NSF.. Other than that write is off

Give him one week, say by next Friday you will cash them. Then do. If they are NSF, you can decide to press criminal charges or go to civil court and/or both