Exam

Yes, you surely can but you need to refer the JEE preparation textbooks. JEE portion is a little advanced from our CBSE portion. So doubts will surely arise but you can take help of Internet tutorials or guides. Even the students who take special coachings for IIT JEE preparation, self study for bet

No, you cannot get a good college with your score.

For enhancing you Vocabulary go for Word Power Made Easy by Norman Lewis
It is brilliant book that helps you build a strong vocab. I would suggest you to buy this book and keep reading it again.
The book does not forces you to memorize any word, it explains the origin and history behind the word and

ICWA, CFA there can be some more.just try to check.

Yes you can appear, your 12th failure wont be a hindrance

In which state are you looking for ? Here is a link for all approved architecture colleges across India - https://www.coa.gov.in/index1.php?lang=1&level=0&linkid=25&lid=26

Hi. here is a link for all approved architecture colleges across India - https://www.coa.gov.in/index1.php?lang=1&level=0&linkid=25&lid=26
According to me SIR JJ college of Architecture is well known for its academics.

Which college are you looking at in both these university's ? Both Universities are well known, but you need to choose the right college in these universities. here is a link for all approved architecture colleges across India - https://www.coa.gov.in/index1.php?lang=1&level=0&linkid=25&lid=26

For your answer you may refer the undermentioned links:-
Kishore Vaigyanik Protsahan Yojana (KVPY) - Scholarships for students interested in Science as a career http://kvpy.iisc.ernet.in/main/about.htm