How to show LIC maturity

The maturity amount must be taxable, so either accept the difference as per notice if as per calculation. Or revise for any difference, by non-acceptance.

When the premium paid on the policy does not exceed 10% of the sum assured for policies issued after 1 April 2012 and 20% of sum assured for policies issued before 1 April 2012– any amount received on maturity of a life insurance policy or amount received as bonus is fully exempt from Income Tax under Section 10(10D). 

as said by Mr. Soni, if your LIC plan satisfies the above conditions, show it under exempted income or under income from other sources