In India, the calculation of leave encashment is typically based on the basic salary. To determine the leave encashment amount for an employee with 66 days of leave bonus, a CTC of $20,000, and a basic pay of $10,000, you would generally calculate it based on the basic salary. However, it's essential to review the company's specific policies and the terms mentioned in the employment contract to ensure accuracy. If the company's policy states that leave encashment is based on basic 50% or CTC, then you would follow that guideline. It's recommended to consult with the HR department or refer to the company's HR policy for precise calculations.