B.Arch

Hello,
Yes, 180 to 190 marks are good in JEE Main exam.

Yes, But you Must have PCM in Class 12th with minimum 50 percent aggregat or candidate must have passed Diploma with Mathematics as compulsory subject with a minimum 50 percent Aggregate.

No, but You can try for Other Pvt colleges & if you had 80 - 85 percentile then you may have Chances of getting B.Arch. Hope it helped.

No, you cannot get a seat in NIT. Try for some good private colleges such as Manipal University which takes Admission on MU-OET. Hope it helped.

Doing B.E. / B.Tech/ B.Arch through distance mode is not valid as per UGC guidelines. So never be pursue. B.Arch through regular mode is the best option. Further both courses also can not be pursue simultaneously through regular mode.

But with 79 percentile it is sure that you can Get any NIT or IIIT if you belong from other state. But still as per your percentile score you can try in HBTI Kanpur. Or better go with some other private institutions like Kalinga Institute of Industrial technology or CV Raman Global University.