Is there any time limit for police action?

I had purchased Land in 1994. The seller had then fraudulently sold it to others. I attempted to lodge a case in concerned PS. They said it is civil matter .. we can't take up unless the court directs so. I approached court and court directed PS and subsequently FIR was registered under IPC 420 etc. 1 month over... no further action from Police. The accused are staying at the address given. Is there no time limit for police to take action against the accused?