Dear Prakash,
Whenever you raise questions on employees' statutory rights or employers' statutory obligations, you should provide complete information about the type of establishment/industry, the employee's capacity of employment (such as managerial, supervisory, or workman), employment status (regular or outsourced), and in the case of rights or benefits, whether they are statutory or arise from the contract of employment. Only then will you receive an appropriate answer.
Not all employees are eligible for leave encashment upon termination of employment. Not all types of leave are encashable upon termination. If leave encashment is statutory, no contract of employment can exclude it.