If it is a small amount of liquid or just condensation in the drip trays then this is normal.
If the drip tray is full/overflowing with liquid then:
1) Check the tank is on correctly:
- Check that the tank screws are tightened and are in the correct place
- Check the rear of the tank and around the rear tank gasket to make sure that the tank is securely in place and that the rear tank gasket is properly aligned
- Once the tank is located correctly fill the tank with cold water to just above the rear tank gasket to check for leaks.
2) Check if the leak is coming from the taps, if it is:
- Check seals and parts are properly fitted - a guide to tap removal and fitting can be found here
- Check seals and parts are properly lubricated
- Check seals and parts for wear - if they have suffered wear and tear then they are likely to be the cause of your leak