How to save capital gain tax ?

Hello Friends i need your help........

1)Mr A One of my client win the lottery form mahada a house property Values Rs 25,00,000 on dated 14/01/2010.

he paid Rs 25,00,000/- to mahada on 28/01/2010. (there is Lock in Period of 5 year)

2) On 20/03/2012  Mr A  sales his property to mr B at Cost Rs 50,00,000/-   he recvied advance Rs 150000 on 20/03/2012 and Balance Rs 3500000 on 31/04/2012 (i.e within Lock in period)

now mr B is prepare Agreement to Sale on 31/04/2012( l.e MOU that mr A will Sale his property to Mr B on Complition of 5 year Lockin period)  with Stamp duty  to secure his right  but mr B will prepare Sale Agreement in 2015. (Becuse Lock in Period is 5 year) 

3) Now Mr A is Purchase another Property at Cost of Rs 6500000 on 28/04/2012.

My question is that

1) Is Mr A Liable to Capital Gain Tax  if yes then form which date i.e on Date of advance recevied or on date of MOU or on date of Sale deed ?

2) How can we save tax i.e long Term or Short term ?

3)And what in Difference betn Agreement to sale and Sale Agreement. ?