While a good number of points will certainly help to get into the top 20 for RSB, I would advise you to focus on the quality of the content. Do not, as is suggested, give a lengthy response to a forum thread for the heck of it. Let it be relevant to the topic under discussion. Secondly, it is incorrect that if you get 1000 points, then you will get Rs.500. Our share in RSB depends on the earnings generated by the site as a whole. Submitting articles, as stated, is conducive to getting better RSB because the points of articles are doubled when considering RSB.
In terms of AdSense, too, the more quality content you put up at this site, the better your earnings. I checked your AdSense profile account (you can check it, too, on your Dashboard page), and you are very much eligible to apply for AdSense if you have not already done so. However, as correctly advised in this thread, you do need to submit a good number of articles. I also suggest you try to answer queries in our Ask Expert section and submit schools and colleges with detailed descriptive content (use the search box before submitting to avoid duplicates). If you can consistently submit quality content for the next three months at least, you will have a fair chance at getting AdSense approval when you apply by year-end.
A footnote- kindly avoid selecting multiple responses in all your threads as 'Best Answer'. Wait for a few days, check all the answers that have come in, and select only one as the best answer, maybe two if really exceptional. What's more, every thread of yours does not necessarily have the best answers, perhaps not even a single one that is so deserving as to be marked so. Use the feature with prudence.
When you make a commitment, you create hope. When you keep a commitment you create trust! ~ John C. Maxwell