Hello, and I hope all is well with you!

Your final merit scores will be calculated by dividing your NATA scores by two, adding the 12th percentage, and then dividing the total amount by two again. Your final merit score is (147/2+89.4)/2= 81.45.

For JEE Main Architecture 2020-2020, you can use Careers360's college predictor.

https://engineering.careers360.com/jee-main-architecture-college-predictor?ici=cp-listing engineering&icn=JEE-Main-Architecture-College-Predictor

All the best.