Pilot

You will be eligible for both the positions after you complete your aeronautical engineering degree. IAF takes entry from AFCAT and CDS for both flying branch and technical entry, for those who are graduates.
For those who come after 12th can enter from NDA.
In AFCAT the cutoff for flying branch is higher than that of technical one.
After you get through the written exam of AFCAT you will be called up for AFSB at any of the airforce station. Once you are recommended by the AFSB you shall join IAF for flying or technical branch. The choice lies with the candidate to go for flying or technical branch.
CDS is a common exam which allows entry for all the three wings of Indian defence services. Here also choice lies with the candidate to give his or her preference for Army, Navy or Air Force.
NDA also allows entry to all the three wings of defense after class 12.

You need to understand that Pilot training is governed and regulated by DGCA and it is irrespective of the flying school you choose to train with. Advanced Aviation Training will also follow the similar eligibility criteria and Requirements and decided by DGCA.
For becoming a commercial pilot, there is a specific eligibility criteria, which you should first be aware of. This is decided on what subjects have you taken in class 12th. It requires PCM to be a pilot. And, even if you have not opted for the same, then you can appear separately for these subjects and become eligible. Further, you should be aware that you are medically fit to be a pilot, so I would suggest you to visithttp://www.dgca.nic.in/medical/medical-ind.htmandgototheclass2nd examiners tab to find out doctors who will examine you for initial fitness. You can visit any doctorate from the list as per your convenience. Once you are done with Class 2nd medical, find out a suitable flying club for you as per your convenience. You can fly in India or abroad. I would suggest you fly in India. Besides finding the club, be aware that you will have to appear for:
1. Air Navigation
2. Aviation Meteorology
3. Air Regulations
4. Aviation Technical
5. Aircraft Specific
6. Radio Telephony
Here, 1-5 are conducted by DGCA and 6 is conducted by WPC. Prepare for these subjects and appear, as exams are conducted every quarterly. For preparation, flying club will help you or there are private instructors available in metro cities as well. You will fly for 200Hrs + Clear DGCA and WPC exams + Clear Class 1st medical, then you shall get your CPL. The next license is ATPL, which you shall be able to apply for once. You will then have to probably fund or self-sponsor your type rating on whatever fleet you are selected in an airline. Then, you finally get a job as a pilot. I hope the process is well explained to you. CPL is an expensive affair. It might cost you around Rs.18-20 Lacs for flying + DGCA exams Rs.500/- each exam + Medicals for Rs.10, 000 + endorsements and license issue fees around Rs.25k + Type Rating around Rs.15 Lacs. So, decide wisely before you enter the field.

Your Mechanical degree will be an additional qualification for you, although it will not be used for any privileges for issuing your CPL.
For becoming a commercial pilot, there is a specific eligibility criteria, which you should first be aware of. This is decided on what subjects have you taken in class 12th. It requires 50% in PCM to be a pilot. And even if you have not opted for the same, then you can appear separately for these subjects and become eligible.
Further, you should be aware that you are medically fit to be a pilot, so I would suggest you to visit http://www.dgca.nic.in/medical/medical-ind.htm and go to the Class 2nd examiners tab to find out doctors who will examine you for initial fitness. You can visit any doctor from the list as per your convenience.
Once you are done with Class 2nd medical, find out a suitable flying club for you as per your convenience. You can fly in India or abroad. I would suggest you fly in India. Besides finding the club, be aware that you will have to appear for:
1. Air Navigation
2. Aviation Meteorology
3. Air Regulations
4. Aviation Technical
5. Aircraft Specific
6. Radio Telephony
Here, 1-5 are conducted by DGCA and 6 is conducted by WPC. Prepare for these subjects and appear, as exams are conducted every quarterly. For preparation, flying club will help you or there are private instructors available in metro cities as well.
You will have to fly for 200 hours+ clear DGCA and WPC exams + clear Class 1st medical, then you shall get your CPL.
The next license is ATPL, which you shall be able to apply for at once.
You will then have to probably fund or self-sponsor your type rating on whatever fleet you are selected in an airline. Then, you finally get a job as a pilot.
I hope the process is well explained to you. CPL is an expensive affair. It might cost you around Rs. 18-20 Lacs for flying + DGCA exams Rs. 500 each exam + medicals for Rs.10,000 + endorsements and license issue fees around Rs. 25k + type rating around Rs. 15 Lacs. So, decide wisely before you enter the field.

Graduation is not a compulsory requirement for becoming a pilot.
For becoming a commercial pilot, there is a specific eligibility criteria, which you should first be aware of. This is decided on what subjects have you taken in class 12th. It requires 50% in PCM to be a pilot. And, even if you have not opted for the same, then you can appear separately for these subjects and become eligible. Further, you should be aware that you are medically fit to be a pilot, so I would suggest you to visithttp://www.dgca.nic.in/medical/medical-ind.htmandgototheclass 2nd examiners tab to find out doctors who will examine you for initial fitness. You can visit any doctorate from the list as per your convenience. Once you are done with Class 2nd medical, find out a suitable flying club for you as per your convenience. You can fly in India or abroad. I would suggest you fly in India. Besides finding the club, be aware that you will have to appear for:
1. Air Navigation
2. Aviation Meteorology
3. Air Regulations
4. Aviation Technical
5. Aircraft Specific
6. Radio Telephony
Here, 1-5 are conducted by DGCA and 6 is conducted by WPC. Prepare for these subjects and appear, as exams are conducted every quarterly. For preparation, flying club will help you or there are private instructors available in metro cities as well. You will fly for 200Hrs + Clear DGCA and WPC exams + Clear Class 1st medical, then you shall get your CPL. The next license is ATPL, which you shall be able to apply for once. You will then have to probably fund or self-sponsor your type rating on whatever fleet you are selected in an airline. Then, you finally get a job as a pilot. I hope the process is well explained to you. CPL is an expensive affair. It might cost you around Rs.18-20 Lacs for flying + DGCA exams Rs.500/- each exam + Medicals for Rs.10, 000 + endorsements and license issue fees around Rs.25k + Type Rating around Rs.15 Lacs. So, decide wisely before you enter the field.