I am a commerce student. Can I do architecture B.Arch without giving the entrance exam i.e. NATA?

Not exactly, though it's the most common route by far. Besides NATA, JEE Main Paper 2 conducted by NTA is another accepted option for many architecture programs. Some states also run their own separate entrance exams for local colleges. So depending on your target college, you might need to prepare

No, NATA scores do not influence the category structure of tuition fees for BArch programme at VIT Bhopal University. The tuition fee remains the same regardless of entrance exam marks.

Yes, students can get admission in Sri University BArch with NATA scores. BArch admission is entrance-based. The final selection is based on academic scores and SSU CET/ NATA/ JEE Main Paper-2. 

Yes, you can get a decent chance of getting admission at Sharnbasva University with a NATA score of 57.

NATA is one of the accepting exams for admission in BArch at Sister Nivedita University. However, it is not compulsory. Aspirants can also get admission in BArch based on their JEE Main paper-2 scores. Aspirants must also meet eligibility i.e. Class 12 with PCM with at least 50% aggregate for admiss