Hii Nimisha!
Now your NATA score will be combined with 12 board marks and after that you will be provided with your final score. Anything above 130 will get you into a good college and a score above 150 is required if you want admission in a government college. Anything between 100 and 130 will get you into a decent college and if your score is below 100 then it might be a little difficult to get into a college of your choice . I hope this information helps you. 
Thank you !

All the best for your future!