As per the Shops and Establishment Act only 5 days per year are [mandatory] to be availed else it lapses and the balance 10 will be taken forward to the next year subject to maximum of 60 leaves. Also an employee can avail up to 8 days of earned leaves for encashment under the Act though not mandatory.
There is no way you can legally stop from settling the leaves so earned at the time of separation.
Thanks and Regards
30th August 2018 From India, Hyderabad