Capital gain in case of property under redevelopment

I wish to know about capital gain on redevelopment of property. Situation as follows:

X & Y had a property with 3 floors of X & 1 floor of Y. This property went into redevelopment & X recd say Rs. 1.5 cr and Y recd Rs. 0.50 cr in csah and one flat each valed by the valuer at Rs. 1.8 cr of X & Rs. 1.20 cr of Y. I wish to know following:

1) whether it is a transfer u/s 2(47)? Whether capital gain tax is attracted?

2) what is the treatment of cash recd by X & Y?

3) how to determine capital gain in this case? whether following calculations are correct?

In case of X, consideration in Cash.                       Rs. 1.50 cr

                                               Flat value.                      Rs. 1.80 cr

                                             Thus, total.                      Rs. 3.30 cr

          Less: Indexed cost of acq, say                     Rs. 1.20 cr

                       Thus, net cosideration.                     Rs. 2.10 cr

                    Less: Inv in NHAI bonds.                      Rs. 0.50 cr

                               Inv in new flat as above u/s 54. Rs. 1.80 cr

                               Thus capital gain.                    (-) Rs. 0.20 cr

Please reply.

Thanks.