Hey Surbhi,

Dont worry if you've lost your certificate. You need to do nothing extra. The easiest way of getting your migration certificate is that:-

1. Locate CBSE office of your area.

2. Go at the reception desk.

3. Tell the receptionist what documents you want.

4. He will give you a form that he will tell you how to fill.

5. He will also inform you how much money it would take.

6. After you submit the form and money he will give you a slip.

7. Then the receptionist will allot you a particular time to collect you certificate by showing that slip.

Hope it helps.

All the best