• Objects, texture related to architecture and built environment.
• Interpretation of pictorial compositions,
• Visualizing 2D-3D objects.
• Analytical reasoning, mental ability (visual, numerical and verbal),
• General awareness of national/ international architects and famous architectural creations 

• NATA - National Aptitude Test for Architecture - for admission in private colleges recognised by Universities.

For private colleges, after getting your NATA score, you can check their websites and contact them for knowing admission procedure.

In order to take admission in IITs for B.Arch you have to qualify for JEE Main exam to be eligible to appear for JEE Advanced then you have to clear AAT (Architecture Aptitude Test) entrance exam. 

After clearing AAT exam you can take admission in IIT Roorkee and IIT Kharagpur

You can check the top colleges for B.Arch with the given below link.

School of Planning and Architecture (SPA), New Delhi

JJ school of Arts and Architecture

IIT Kharagpur

Centre for Environment Planning, Ahmedabad

Sushant School of Art and Architecture, Gurgaon

Chandigarh College of Architecture

Guru Nanak Dev University, Punjab

As you already mentioned that you have filled NATA 2018, you can get admit into your choice of college as you mentioned, ‘Sir JJ college of architecture’

During admission through NATA, the college considers your NATA score as well as 12th Board marks, 50-50%.

E.g. - If your NATA score

There a few common things for studying in USA. You will need 2/3 LOR's which should be from your teacher/employer who know you well. Your GPA should be above 3/4. You will need to write a Statement of Purpose (SOP) which you will need to help tell the universities your

JEE Mains Paper 2 and NATA, both the exams are conducted for admission into 5 years Architecture courses. This being the similarity, there are also many differences between these two courses.

• JEE Mains is conducted by CBSE whereas NATA is conducted by Council of Architecture.
• The duration for both the

Depends on your choices.

All the very best and good luck.