First you read the mortgage deed. Normally a sale of the mortgaged property is barred. Still a sale can be done with the permission of the bank. If the bank will not give you permission unless the mortgage is satisfied still you can go for the sale if the purchaser is ready to face the consequences and you are ready to face action under civil and criminal laws.
No body in the world except the courts can restrain you from selling your property. Go ahead.
if the land is mortgaged before selling the property you have to redeem the property from the bank you have mortgaged if you want legally to sell. since your property is mortgaged you can not validly sell the property. provided before making a sale you can enter into an agreement with the buyer to redeem the mortgaged property from the sale consideration.