How to prepare for ISRO Scientist written test and interview?

First let me Clear that I’m not in that,
I’m sharing just friends review.

Written exam

• In order to clear the written exam, one should be experienced enough to judge his/her weak areas and prepare accordingly. The same applies for other exams like BARC, whose examination pattern are similar to that of the ISRO.
• Solving previous year papers with a constraint of two hours to solve a paper. This helped  in improving speed.

Interview

• Well, if you are lucky to clear written exam,the next step would be to keep visiting ISRO career website weekly for the interview schedule as there may be a large delay in receiving the interview call letter. In the applicant’s login page also they put the interview venue details. The interview schedule is published on the website normally within 10 days after the result declaration. And, interviews start approximately one month after the result declaration.
• During the interview, you will be sitting in front of a panel of 7-8 senior scientists from ISRO with a white board behind you on which you are supposed to solve problems.
• Although, they will ask you about the subjects you prepared, they generally deviate and ask questions from other subjects too (although the easy ones). Design problems will be from your favorite subjects only. You will be asked about your recent project – job project or final year project and to explain them on the board.
• While preparing for the interview, question everything with a rational mind and try to figure out why it is done this way only. Scientists are mainly interested in ‘why’ of every situation.

Hoping that this would help some in their preparation.