Required Suggestions
* How we can clear the title of said land.
Who is having he title document, i.e., registered sale deed, whether your vendor is having perfect and marketable title on his name, then verify the same through the title search/tracing from the registrar's office to confirm this title.
* is it worth to do the registry of said land.
Without confirming the title of the vendor by verifying the title by tracing it to the previous owners, it may not be advisable to purchase the same.
* are we able to do any construction on such land like setting-up the park and hotels activities as its totally unpolluted and no harmful to the environment.
You have to apply for conversion as per the local law and the formality prevailing.
* are we able to convert that land into non-agriculture (if forest settle down the P.F. Issue)
First you have to get clearance and no objection from the forest department and then from collector.