A rural agriculture land is not a capital assets u/s 2(14) of Income Tax Act, 1961, thus no capital gain tax is charged on sale of rural agriculture land.
https://www.indiabudget.gov.in/budget2013-2014/ub2013-14/mem/mem1.pdf
please visit on above link and read on page no. 13, in this government defined which agriculture land is rural and which is non rural.