you have to contact a local lawyer . find out whether title is clear and market able . then decide whether to buy plot or not . decide on terms of payment . enter into agreement with seller for plot . pay stamp duty on sale deed as per market value of property . generally it is 5%of market value of the plot as per ready reckoner rates . your lawyer would do the needful

I think you are asking for loan from bank.If so,you can enter in agreement to sell defining the terms and conditions of sale after paying some advance may be around ten percent.On basis of this bank will be able to decide on loan.

You should engage a lawyer for making the agreement. Before signing on the dotted line on the agreement you should carry out the due diligence test to ascertain if the title is clear and free from any legal dispute pending in any court of law. If the title comes out to be clear then go ahead with the proposed purchase by incorporating the terms of payment in the agreement itself. After the agreement is made it will have to be stamped at the market value of the property.