1. Can the occupants claim possession of the land on the basis that they have been cultivating it in the last 10-12 years? Even though they do not possess any legal document such as a sale deed/agreement.
==No, by mere cultivating for 10-12 years will not give them right over your land. They might have created some bogus document. We can find out by verifying the revenue records. This is complicated work. If you are interested I can take up your case. Contact me through Phone consultation.
2. Can we evict them legally in a peaceful manner with the support of the court or local police? Or is there a law which prohibits eviction of any individual?
==You have to take support of the court. You can evict them. Local police will not interfere into civil matters.
3. As per the revenue officer, they have been given "oral" orders to register lands on the basis of "current occupants". Is this tenable in the court? Or is there any such order?
==There will not be any oral orders. The orders will be in writing only.
4. Since we have delayed this action by many years, does it effect our chances if we approach a court?
==It may effect to some extent, but by hiring a good experienced laywer you can win the case.