1) enter into MOU with the seller
2) it should be mentioned that 5 lakhs has been received as consideration for sale of land
3) that seller shall execute regd sale deed in your favour within period of 3 months or so
4) that in the event he fails to execute registered sale deed he would refund Rs 5 lakhs paid with interest at 12 per cent per annum
5)tht seller shall obtain consent of LDA for sale of land to you