Dear sir,
Have you shown this amount sale of agricultural land in your return of income?
If the answer to the above is yes, and If you can prove that 50 lacs is out of the sale proceeds then there is no problem.
Though, it is very likely that tax department will ask you the questions but you can respond.
Please feel free to call/revert in case of any doubts
Thanks and Regards
Abhishek Dugar
CA CS. B.Com