India

First, take your Senior Secondary Examination (I.e. your 12th class board exam) and score at least 60% in all the subjects.
Then you have to try for various medical entrance examinations like AIPMT, AIIMS, JIPMER, various State PMTs, etc. and achieve a good rank (it is easier said than done, although the level of examination is not that tough overall, but the number of seats is quite less which is why the selection rate is very low, even lower than IITs).
And then finally, complete your MBBS from a reputed medical college.
Congrats! You are a doctor!
But most students after MBBS try to specialise in a specific field (I.e. MD/MS). For that, you have to take the PG (post-graduate) medical entrance exams like AIPGMEE, etc. (Even more tough) after completion of your MBBS.
After PG, some opt for M.Ch./DM, etc. but that's completely up to you.
Take years of experience and then probably you'll get selected to be onboard on AIIMS as a panel doctor.

After completing your school, you can appear for entrance tests conducted by the institutes mentioned below:
1.Film and Television Institute of India
2.Satyajit Ray Film and Television Institute
3.Government Film Institute
4.Ramoji Film and Television Academy
5.Biju Pattanaik Film & Television Institute
How is Competition?
Cinematography is a popular major in most colleges who offer the course, and so it is expected to get very competitive in the future. Experience and Seniority in the field often are imperative to get ahead of the competition. However, cinematographers are expected to enjoy stable employment prospects, thus making it an attractive industry to enter.
Employment of Cinematographers is expected to increase 11 % between 2008 and 2018, according to December 2009 data from the Bureau of Labor Statistics. This rate of growth is about average compared to other careers. This ensures that the competition remained fierce in this industry with new talent graduating every year and entering this field.
What are Salary Prospects?
Cinematographer's earnings vary, depending upon location, experience, and employment specifics. In the United States, an average salary of $40,000 per annum is paid to a cinematographer; however, there are also jobs which pay six digit salaries. Cinematographers tend to make more money working for motion pictures rather than working for the television industry.
In India, a cinematographer who has just joined the industry is paid Rs. 84,000 Rs. 96,000 per year. As the cinematographer becomes more experienced, his/her salary rises to Rs. 480,000 Rs. 600,000 a year. The salary also depends upon the project on which the cinematographer is working on.