Hiii
Since you have studies PCM in class 12th, this has opened up a variety of fields for you.
First lets go to the most common one  ENGINEERING.
JEE MAINS will be the common entrance exam for all engineering colleges except IITs. For that you will have to qualify JEE mains with top ranks and then also qualify JEE advance with good marks.
Also some universities and colleges conduct their own entrances like SRMJEE is for SRM university, Symbiosis entrance exam etc.
 Coming to other options. Here is a list of few things.

• BBA-MBA
• BSc
• BA
• Bcom
• LLB
• CA
• BFA
• Hotel management
• Mass communication and journalism
• Theatre

All these would lead you to a good future if you are interested in the subject you choose. Now coming to your confusion.
So the first thing you need to do is self analysis. You have to judge your interests.
Let me explain some of the courses above in details
1. BBA-MBA: This is bachelors in business administration and masters in business administration. If you think you can be good in management and administration, you can go for this option. Mba graduates earn a good amount of money and are recruited as Managers, Sales head, etc or also in the administration department.
2. Engineering:I personelly would suggest you to go for engineering in abroad if you wish to go for it. You can appear in SAT exam and study in foreign country and secure your future with great job opportunities and salary. Btech and Mtech will settle down your life. But remember if you are not interested in this then do think once before choosing this option.
In engineering there are many options like CS which will be about computers and technology, programming etc. Next is Electronics and communication, then we have Civil, next will be mechanical and so on. Choose the field wisely as per your interest. I will suggest CS or EC. this has good job opportunity.
3 Architecture:If you are interested in construction design and planning etc then you can go for architecture. Apple for JEE mains paper 2 for B.arch and also you can go for NATA exam these are considered by all the colleges across india for admission. In this field you can earn a very good amount of money if placed in a correct company.
4.Journalism and mass communication:  If you find yourself inclined towards or interested in media actiities etc then this one can be a field for you. Some courses include- 
BA journalism and mass com.
Bachelors in journalism
BA Mass com and media studies
BA mass media.
5. Law: You can also opt for law courses and become a lawyer if you are interested in court scenarios. For studying LLB you will require a bachelors degree first. SO you can simply go for BA-LLB or BBA-LLB which ever you feel comfortable.
        There is much more you can explore but first of all you need to understand your area of interest. If you feel like knowing about some particular field you can feel free to ask.

Hope this helps
Thanks!!

What is your confusion?