I purchased a mobile home to rent . i had it moved to my land, I paid for moving and set up, underpinning ,where do I deduct these cost

You will not be able to deduct the expenses relate to moving and setting up a mobile home that you are going to rent.

Instead all these costs will be added to the cost basis in the mobile home and when you do make the mobile home available for renting, you will be able to claim an annual depreciation expense on the cost basis on the mobile home (which will included these additional moving and set up expenses).