I don't know who gave you such information but unless you have completed your professional examinations which are four in number and which range rover four and a half years and you have completed your compulsory rotatory internship posting for one year you are not legally allowed to practice medicine or do any other side income by medical practice
yes you can be self employed in something which is not related to medical practice like teaching for giving tuitions or maybe even pursuing other resources writing or sketching or even find out such as music or dance that is completely different issue all together but medical profession does not facility to income why are its merits till you get the degree

Dear Kiran, ideally no medical professional is allowed to practise either independantly or in private without the completion of course. You are not taught treating various diseases and medical conditions right away in the first year. You are supposed to learn various subjects over a period of 5 years and there is a reason for it. It is not like a code that you write wrong and yoy can edit it. It is a human body and there cannot be any erasings.  So just to answer your question you cannot start working right away from the first year.