NATA

Unfortunately, you can't. National Institute of Technology accepts only JEE Mains paper 2 rank to admit students in B.Arch. IITs accept NATA score. However, there are some other colleges which accept NATA score.
Hope it helped.

Yeah Bhavana. You can download JEE paper 2 question papers from ( www.jeemain.nic.in) .
There you can find question papers for last few years I.e. 2017, 16, 15, etc.

If you have the desire, you can do hard work on your own and come out with flying colours and I know a lot of people who have cracked both the papers without joining any coaching class.

Please refer to the link provided below via which you can navigate to the SILICA website. Once there, you will have to provide your contact information and then the coaching institute will provide you course details and fee structure.
Link: http://www.silica.co.in/

(Board score/2)+(Nata score/4), if
it is 80 then you will get a top college.
If 75 then you will get a good college.
If 70, you will get an average college.
If 60, you will get a decent college.
This rule is for general category and candidates belonging to outside state category, for first merit list.
Hope this helps.

Hi,
Please refer to the link provided below for details on admission criteria and eligibility to gain admission into the college of your choice. Your 12th results seem to be fine but your NATA score is low. You will get a more accurate picture if you get in touch with the college admissions bureau. You could also try for admission through management quota.
Link: https://www.shiksha.com/college/sir-j-j-college-of-architecture-mumbai-24830

Yes, you can appear for the NATA exam after completing your HSC.

NATA qualifying examination scores are valid for a period of two years starting from the date the individual appeared for the examinations. Admission into an institute accepting NATA scores is not possible before you have appeared for the exam.