Section 50c applicabilty on sale of rural land which is 10 km away from municipality and converted to residential land 3 years ago

Dear all, Please solve the query that a land which is 10 km away from municipality and land was used for agriculture purpose 3 years ago but it is changed to residential land in Registrar Office. Is it still continue to be agriculture land at the time of sale and also the applicabilty of section 50C on this sale transaction ?