Design

If you are not taking any tuitions, then you can just practice on your own, give exams using the online sample question papers, work on your drawing skills and just keep yourself updated with current affairs. Basic English grammar, Logical reasoning and Maths of class 10th should also be worked upon. And right now your priority should be 12.
Good luck.

It starts from July every year.

You've two options. First thing is that you can take coaching classes for NIFT in your locality and on the other hand if you have the confidence on your learning then you can afford a guide that are specialised for NIFT (I personally recommend ARIHANT's guide) and do study on your own. Coming to consideration of subjects. You'll have to be good at quantitative aptitude. English grammar. Gk and current affairs and logical ability for the GAT. For CAT you just have to focus on your drawing skills and creativity.

Hi Aditya Singh,
The fee for B.Des. in User Experience Design is INR-120000/year

No, according to my knowledge, you cannot do diploma in fashion designing immediately after 10th class but you can do polytechnic courses for fashion designing. You have to complete intermediate.

Hi Chaitra Shree,
Its a 6 to 9 months course , classes are held in weekend for a separate badge but the duration can extend in that case. You need to check about the timings and other detail as the weekend badge will depend on the number of students enrolled for it.

Check out the link below for the list of courses/colleges for fashion designing :
https://www.shiksha.com/design/fashion-design/colleges/colleges-india.

Hi Farheen, Please find the link below:
https://www.shiksha.com/design/communication-design/exams/nid-entrance-exam.

Architecture as a career opportunity is better compared to Interior Designing. Architecture is a Degree Course of 5 years unlike Interior Designing.