I belong from a very poor family and I need to earn near 3-5 lakh rupees per month so in which field I should try???

Nandini, this might not be the answer you are looking for right away. Remember when they said Rome was not built in a day? This is one of those cases. No job pays you 3-5 lakhs per month right away. There are jobs that pay you. Like if you complete your MBA from the IIMs, they have an average package of 40 lakhs -60 lakhs and that might help you achieve your dream. But for that you need to complete your Bachelor's degree, appear for CAT and then get a seat in an IIM which means you need an amazing academic record starting from your 10th. You will need atleast 98 percentile and above for a seat in a IIM. Now there are other professional courses like CA, CS, ICWA, etc. But they do not pay you that package atleast for the first 5-7 years and again all this depends on how hard you study and how hard you work. If you expect a company to spend 3-5 lakhs on you per month, your academic profile and work culture should be above everything else. You haven't mentioned the class you are studying in but this is the path that you should be following.