Science

Hello Aarohi,
Earlier architects would do all the design work, both exteriors and interiors themselves. Of late people have become more conscious of the design, layout and placement of their interiors, for offices, factories as well as residences. This has opened the door for a large number of professional interior designers. Most interior designers specialise in a particular area. For example, some may concentrate on business design, while others focus on residential design and landscape designing. Still others may specialize further by focusing on particular rooms, such as kitchens or baths. With a clients tastes, needs, and budget in mind, interior designers prepare drawings and specifications for non-load-bearing interior construction, this includes choice and decoration of walls, floors, roofs, choice and placement of furniture and other indoor objects, window treatments and other indoor objects, lighting and control of visual and sound effects.
Interior Designer should be aware of the change in trends and keep up with the latest styles. Interior designing as a course has become popular in the last few years, there are only a few institutions offering reputed programmes in interior designing in India. School of Interior Design, Ahmedabad offers Five-year programme and J.J School of Arts, Mumbai offers 4 years Bachelor of Fine Arts (BFA). Unlike many other careers, design inevitably requires both a strong aptitude as well as a creative talent in the field.
Interior design is one of the fastest growing professional fields. There are lots of employment opportunities for interior designers in various fields. Interior Designers can find employment with architects or architectural firms, builders, public works department, hotel and resort chains, hospitals, town planning bureau, regional and metropolitan development works, private consultancies, studios and theaters and exhibition organizers. etc. They can also set up their own business. Once they make a name, it is a very lucrative profession.
Interior design offers excellent opportunities for those who wish to be self employed, or work part time. It is one of the few professions where one can operate from home with a minimal investment.

Hi Nipun,
You did not mention your subjects but here are some options after PCM:
B.E./B.Tech
B.Sc
B.Arch
Defence
Navy
and so on.
If you have interest subjects other than engineering, you can see B.Com, BBA, B.Sc-LLB etc.
Competitive Exams after 12th PCM
Joint Entrance Examination (JEE) Main
JEE Advanced
BITSAT
VIT University Engineering Entrance Exam (VITEEE)
COMED-K
State Level Engineering Entrance Exams
Indian Maritime University Common Entrance Test
Indian Navy B.Tech Entry Scheme
National Defence Academy and Naval Academy Examination (I)
Indian Army Technical Entry Scheme (TES)
You have to specify what you want to study and check for related entrance exams accordingly.

Naval Science:
A program that focuses on in-depth professional study of naval warfare and related combined/joint operations at the tactical, operational and strategic levels. Includes instruction in maritime security, naval war-fighting, naval tactics, naval strategy, operational art, planning and conducting joint operations, command and control, civil-military relations, information networking, leadership, ocean and nearshore operations, and related subjects.
Marine Engineering
Marine engineers are skilled individuals involved in the design, construction and maintenance of vehicles and structures used on or around water. Marine engineering technology and techniques are used to create cruise ships, oil platforms and harbors. A Bachelor's degree in marine engineering is the minimum requirement for career entry, and graduate programs in this field are also available.
You can go through NDA or through CDS in Indian Navy and if you want to do in any specialisation then go for Marine Engineering.