Buying agriculture land in uttrakhand

We are looking to buy a plot in uttrakhand in the hilly region of almora while we are from Delhi region and not from uttrakhand The mediator has shared us that he is having agreement with farmers to sell their land on the hills . He is selling a plot from a hill of about 1.25 nalli around 300sq yd. Our question is he informed that buying 300 sq yrd in his agreement he didn't mention it is agriculture or residential. However, as the land is from farmers so it will be agricultural land. We are assuming that as he didn't display any of the documents related to that . 1)Question-How we can know we if that is agriculture or residential land near almora he will be selling us? 2)Question2 -Can we have house construction on 300sq yd for personal use on agricultural land(assuming the land is agriculture) without any permission?If not what permission and documents we will require and the approximate cost for that? 3)Question3 -What if we don't construct any house on agricultural land and just want to resale.Can we resale the land directly in agriculture without converting it to residential? 4)What documents shall we ask from mediator to confirm if we verify that the land is fine to go ahead and buy?