Can we sell?

My parents bought a parcel of land last 2012, paper is only deed of declaration or something of that name. We tried to process it since 2023, but details do not coincide like lot numbers and lot size. It was surveyed once, the engineer then died not so long ago, was transferred to another engineer after the death of the previous, yet, no movement or changes still. We decided to sell it to a very low price just to ease from the stress, farm lot, province here in Mindanao, with fruit bearing trees throughout the property, a portion of river is within the edge of one side, bought 1 whole property but divided by a barangay road, 1 part belongs to adjacent municipality. Roughly 4 hectares, would willing to sell for 2 m