NATA

There are three main exams one need to take for taking admission in B.Arch:
JEE - Covers all IITs, NITs and central government funded institutes
NATA - For private colleges and universities across India
State University and private university entrance tests
Before preparing you need to first decide which the target competitive exam for you is. All these three exams have different pattern and marking criteria. Syllabus is more or less same having Mathematics, Aptitude Test & Drawing Test as major sections. The weightage and scoring pattern is different.For JEE: http://jeemain.nic.in/WebInfo/pd
For NATA: https://www.nata.in/2016/Portals
For state universities and private universities logon to their websites. If you are a meritorious student and sure you can compete among lakhs of students to make room for yourself in few thousand seats available in government. Colleges put all your effort in JEE. If not then look for private colleges and their previous year's cutoff for NATA score and state university entrance exams. Nowadays, private colleges are also as good as IITs in terms of education and exposure.
Colleges which are covered in JEE you can complete your entire 5 year course in INR 50,000 to 1.5 Lac including hostel fee, etc. On the other hand in NATA covered private college INR 1.5 Lac is fee for each semester plus hotel and living. Some private colleges also have lower fees like 75,0000 per semester. State funded government. Colleges have fees requirements form INR 5,000 to 35,000 per semester.