Please do post the WinMTR report for 100 packets for Jay3 server.
Is this 'krrrr' sound you mention only at first, during/before you dial the number, or during the call? If it is happening while you are talking to people, then you will need to call BSNL, and tell them about your problems (unclear voice(s) while making a call). Having your modem and phone on separate jacks is not a problem, but it can introduce new problems. So I have some recommendations. Unfortunately, these are technician's recommendations, so you may need someone to come out to your house.
1. Plug your modem/router into the "home run" jack- that is, the one closest to the box that is on your siding (the wall on the outside of your house). And If you *do* have a phone plugged in that is not into the modem, you *will* need a DSL filter. It looks like this:
If the phone is plugged into simply a jack in the wall, this would explain why your phone makes a 'krrrrr' sound, and even why you have bad ping while someone is on the phone.
About your plan... I am sorry to say that it is shit. 1GB is *very easy* to go thru, and 512kbps is a very poor speed. At that point, if you could just get 2mbps constant, that would be good.
I don't know if there is a solution that does not require money. You (or your parents) would need to call BSNL and explain to them that you use more than one GB, and that 512kbps is too slow for you (ANYONE TBH- it is too slow for the world, these people need to f--k off and die imo).
I would also mention to the company representative that you do online gaming and you are looking for a stable, but reasonable speed connection at a price that will not make you 'broke'. You may get lucky and get a free speed upgrade.
512kbps is too slow for online gaming FYI. If you would like me to explain, let me know, and I will post information regarding bandwidth, speed, and ping.