Normally, the corporates have three types of Leave viz. Casual Leave, Sick Leave and Earned Leave (Annual Leave). Assume that you have following leave in your company.
(a) CL is 12 days pa (unavailed leave at the end of the year will lapse - normally accumulation or carry forward is not permissible)
(b) Sick Leave is 12 days pa (accumulation / carry forward is permissible in some companies - say - accumulation limit is 30 days)
(c) Earned Leave is 20 days pa. (accumulation / carry forward is permissible in some companies - say - accumulation limit is 60 days)
Your notice period is say - 60 days (some companies may operate on 30 days / 90 days).
If you resign from the Company, you have to give 60 days notice or salary in lieu of notice or it can be adjusted against your accumulated leave - both SL & EL. Balance leave should be encashed by the Company. In case you do not have enough leave, you have to pay for balance days.
If you are terminated from the Company, the Company has to give you 60 days notice or salary in lieu of notice. In addition, they have to encash all the Leave (including unavailed CL) available at your credit and pay the same to you.
Gratuity is a different one and as per the Act, if you have completed five years, they have to pay the amount and they cannot adjust any amount against Gratuity.
Hope I have clarified your query
Regards
A B Srinivasan