Answer from by Praveen Bhargav, Managing Trustee, Wildlife First:
After settlement/acquisition of rights and final notification of such private agricultural lands as a National Park, cultivation or fresh clearance amounts to a violation of Sections 27 and 35(6) of the WLPA, 1972. The penalty on conviction as prescribed under S 51(1) is imprisonment of not less than 3 years which may extend to 7 years and with fine which shall not be less than ten thousand rupees.
The situation that you are probably referring to could be about private agricultural land enclaves/enclosures within the boundaries of a National Park. If that is correct, cultivation within the private agricultural land is permissible but extending it by fresh clearance is a violation as described.
You can bring it to the notice of the local forest officials who are empowered to initiate action by booking a case and initiating prosecution before the jurisdictional Magistrate. If no action is initiated, you are empowered to issue a notice to the Chief Wildlife Warden under Section 55 (c) of the WLPA along with photographic and documentary evidence. If no action is initiated at the end of 60 days, you can move a Complaint before the jurisdictional Judicial Magistrate First Class for which you will need a lawyer.