NATA Scores

Yes, chances are high that you may get admission in Rizvi COA. Visit this link to check B.Arch colleges based upon your rank:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor?utm_source=connect&utm_medium=CR_JEECP&utm_campaign=6919840
Then visit this link for various colleges which provides you brochure:
https://www.shiksha.com/architecture-planning/colleges/b-arch-colleges-india.

Yes, the NATA score will help you along with your 10+2 score.

Yes, you have a good chance of getting into CCA. Visit this link to check B.Arch colleges based upon your rank:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor?utm_source=connect&utm_medium=CR_JEECP&utm_campaign=6919840
Then visit this link for various colleges which provides you brochure:
https://www.shiksha.com/architecture-planning/colleges/b-arch-colleges-india.

87 marks in NATA is fine, what is your class 12th score. Government seat is a little difficult if your 10+2 marks is lesser than 90%.

Yes, you have a very good chance of getting a seat in Vaishnavi SOA.

You have a good chance of getting admission in good colleges depending on your 10+2 marks, also your region where you want to join.

It looks a little difficult getting a merit seat in Rizvi.
Visit this link to check B.Arch colleges based upon your rank:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor?utm_source=connect&utm_medium=CR_JEECP&utm_campaign=6919840
Then visit this link for various colleges:
https://www.shiksha.com/architecture-planning/colleges/b-arch-colleges-india

Click on the link and watch the video till end. After watching the video follow the steps as per described in the video. At the end you could predict the list of colleges offer admission to you on your rank basis. https://youtu.be/hOlit6Un7l0.

Go and visit their official website, and from there you can easily understand the procedure of their counselling from registration to the documents verification.

Yes, of course. You are eligible for architecture. This score is enough for admission to architecture campuses.