Gratuity exemption limit

The dates are 10 lakhs received in Dec'17 and another 10 lakhs in June 2018.

As  your retirement date being 30.11.2017, you would be eligible for 10 lakhs exemption onlt.

Employees covered under payment of Gratuity Act, 1972
Sec 10 (10) (ii)
Exempt - Least of the following
1. Gratuity Received
2. Maximum sum - Re. 20,00,000
3. 15/16* Last drawn salary * no. of years
service completed and part there of in excess of 6 months.

Other employees
Sec. 10 (10) (iii)
Exempt - Least of the following
1. Gratuity Received
2. Maximum sum - Re. 20,00,000
3. 1/2 * Avg. salary * no. of years service completed.