B.E.

Be in top 20 percentile of the board. If you are CBSE board, then 75 % is must.

Hi, the minimum eligibility as per council of architecture is: Only candidates who have the following credentials shall be eligible for admission to B.Arch course. I. Qualified through the recognised aptitude test in Architecture NATA or equivalent)
ii. Have gone through any of the following curriculum with marks as prescribed below: (a) Secured 50% marks in Physics, Chemistry and Mathematics and also 50% marks in aggregate at 10+2 level examination.

Well, what you have to understand is that a B.Tech is an engineering degree (in one of many fields so I can't make a direct comparison) and a B. Des is not. It's focused on other things including but not limited to user experience, HCI, ergonomics, etc. The course isn't similar to those on mechanical design. Students pursuing both degrees share a common year of coursework but beyond that, the only common courses that they have are humanities courses and certain open electives.

The minimum eligibility for getting admission in NITs is 75% in 12th + JEE Mains rank. So, 12th marks Re considered at the time of admission for B.Arch programme.

Not every student gets a seat in JoSAA counselling. You will get a seat on merit basis only. Those who have scored good in the entrance, can expect a seat. But those who are having less rank go for private colleges and take admission.

Why not? It depends on requirement over there and your performance during selection criterion. Regards.

For 2018 admissions, it was around 95-100 MHT CET exam.

If both your interview rounds at XISS, Ranchi went really well, then you can surely expect getting selected for its PGDM program.
Hope for the best.
Good luck.

85.2 percentile in CAT was the cut-off in 2018 at Fore. Your profile seems good; just focus on getting a score above 85 and perform well in the interviews.
Good luck.