You can check the interest amount in your statement,
1. Go to profile section from the top right corner of your home screen
2. Click on cash balance Reports and statements
3. Click on Cash ledger
You will also receive a monthly interest statement on your registered email address once the interest is charged

If you want to know the interest rate beforehand, you can call the customer service at 1800-209-9191, from Mon-Sat between 8.30 am-6.00 pm