Transfer among relatives.

As per Stamp Act of WB - Father's brother is not a relative, so any transfer between them has to be done vide sale deed.
(Current Stamp Value of land 50 Lakhs)

but as per Income tax Act, they are relatives, so transfer among them will not be taxable.

how do I plan the transaction such that I am not liable to pay Capital Gains tax.
also is there a way to not decrease the tax liability if sale deed is registered?

thanks.