If you are pursuing a graduation degree, which completes in 3 years for example: B.Com, B.Sc., BMS, BAF, etc. then you can sit for the CAT. If you are completing graduation in 4 years like engineering or diploma courses, then you are allowed to take the CAT exam in your fourth year.

It is a really great thing to start preparing for an MBA during your college, if you gain enough work experience or by internships, your resume will also be preferred among others, without the experience.

You can prepare by taking mock tests, learning the exam pattern, management of time, preparing from the right study materials, etc. You can also study with your friends group and help and learn from them. Also solve previous years papers to get an idea about the exam.

There is no age limit for CAT. An aspiring candidate can appear for it (to get an idea) in their 1st year of graduation itself but won’t be able to get admission in any B-school. There are 58 year old candidates in the exam center who had a fascination for such entrance exams. In short, you can appear for CAT at any age.

You need to score as high as possible. You are unable to change the marks you got in your classes 10 and 12. If you focus too much on your previous results, you cannot concentrate on the preparation for CAT.

So, try determining your strengths and weaknesses, and work on them accordingly. Read the newspapers and magazines like The Hindu and The Economic Times to enhance your vocabulary and language skills. Try doing mental maths as it will be beneficial. Solve sudoku and other brain teasers like puzzles to sharpen your problem solving skills. 

Try to not focus on your 10 and 12 results, instead thoroughly prepare for CAT with utmost concentration.

There are many colleges which give less weightage to academics like FMS Delhi, NMIMS Mumbai, IIFT Delhi, JBIMS Mumbai, KJ Somaiya, IIT Delhi or Mumbai, GIM, IMI Delhi, IMT Ghaziabad, etc. Try to go for any of these institutions if you are worried about your academics.

No, a science student will not be able to sit for the CAT exam after their class 12th. This is because the CAT exam facilitates admissions for MBA - which is a Masters or Postgraduate degree. 

In order to be eligible for joining a masters curriculum, you will need to finish a basic graduation (Bachelor's degree). 

Since you are from the science background you can opt for B.Sc. and then pursue MBA. You can also go for BBA, B.Tech, etc. Once you finish your graduation you can sit for CAT.

The most important thing is your profile, it plays an important role in deciding what colleges you get a call from. If you have an overall decent academic profile, you might be considered for better colleges.

So with the percentile range you have mentioned, and you are a general category student, male and possibly an engineer, receiving calls from the leading IIMs will be difficult. 

However, there are other reputed B-schools with lower cut offs and with lesser weightage to profile. You can find their eligibility criteria and match it to your requirements.

Yes, you can easily get into XIMB HRM with your NMAT score. In Fact, there are many other B Schools that accept NMAT scores like

The colleges in order of their ratings are-

• NMIMS Mumbai (212 and above)
• NMIMS Bangalore (199 above)
• NMIMS Hyderabad (190–195)
• XIMB (190–200)
• NMIMS Navi Mumbai (185+)

Honestly, only NMIMS Mumbai and Bangalore are worth investing in. 

One can certainly apply for the exam again but they must bear in mind that the cost of the exam is costly and you will have to apply separately and fill out forms for the exam as well as colleges again.

NMIMS Mumbai lays great emphasis on your work experience So, even with an average performance in CDPI one can convert a call.

NMIMS Mumbai enjoys a locational advantage being located in the finance and business hub of the country. It is among the 15 top B schools in the country