Hello Sanika, 

You can surely appear for BITSAT as there is no requirment for appearing in an entrance exam.

The only thing which you need to worry is your prepration.

You can easily apply for BITSAT and can appear there but chances are less that you will qualify for it.

So instead of wasting your money, I suggest you to prepare for the test and then appear.

At this point, you should start taking things seriously as it is the peek time for your career and be sincere towards your work.

Once you become mature enough and start taking things seriously, i believe you will surely come up with flying colors.

All the very best!