Of course... Go your way and follow your dream and you will reach it!
Success in Chess

I am 15 years old and have a fide rating of 1656, is it possible for me to achieve a GM title.
P.S: I was 1203 2 years back

Yes, of course. You can achieve anything you want but sticking exclusively to the forum doesn't help.
Possibly of interest:
https://www.chess.com/article/view/can-anyone-be-an-im-or-gm
What It Takes to Become a Chess Master by Andrew Soltis
https://web.archive.org/web/20140708093409/http://www.chesscafe.com/text/review857.pdf
100 Chess Master Trade Secrets by Andrew Soltis
https://web.archive.org/web/20140708094523/http://www.chesscafe.com/text/review916.pdf
Reaching the Top?! by Peter Kurzdorfer
http://www.thechessmind.net/blog/2015/11/16/book-notice-kurzdorfers-reaching-the-top.html
http://www.jeremysilman.com/shop/pc/Reaching-the-Top-77p3905.htm
What It Takes to Become a Grandmaster by GM Andrew Soltis
https://www.chess.com/article/view/don-t-worry-about-your-rating
https://www.chess.com/article/view/am-i-too-old-for-chess
https://www.chess.com/blog/smurfo/book-review-insanity-passion-and-addiction
http://www.nytimes.com/1988/09/26/books/books-of-the-times-when-the-child-chess-genius-becomes-the-pawn.html
https://www.chess.com/news/view/is-there-good-money-in-chess-1838

if your improving, GG
work harder; don't shy from playing against strong players and be ambitious
Note that asking the forums about "IF" is in fact rather pointless. we don't know you- and Most of us have no clue how to train Well enough to be a GM.
you can find a coach that does, however. and that guy can give you a lot of advice.
everything is still possible with a good Trainer and a Lot of effort. play a Lot of rated games, analyze them with a coach and calculate appropriate exercises for your Level of play. and also study the classics from former Champions. I hope i could help you :)

However, and it's a very important "however", you must accept that there is no guarantee that you will become a GM, even if you put everything into it. Strong desire to become one also doesn't guarantee it.
You should also consider whether it is a good idea to pursue the GM title. Since it requires many hours of studying in regular basis it will mean that you'll be taking your time out of other activities. Main one is study time for school. If you want to graduate and go to a university you must put everything into school to get highest possible grades(marks?). If you spend hours on chess you will sacrifice study time. There are also extracurricular activities you may want to consider.
Just make sure you evaluate this goal very carefully so that you don't damage your academics and regular life for the sake of chess.
"... Many aspiring young chess players dream of one day becoming a grandmaster and a professional. ... But ... a profession must bring in at least a certain regular income even if one is not too demanding. ... The usual prize money in Open tournaments is meagre. ... The higher the prizes, the greater the competition. ... With a possibly not very high and irregular income for several decades the amount of money one can save for old age remains really modest. ... Anyone who wants to reach his maximum must concentrate totally on chess. That involves important compromises with or giving up on his education. ... it is a question of personal life planning and when deciding it is necessary to be fully conscious of the various possibilities, limitations and risks. ... a future professional must really love chess and ... be prepared to work very hard for it. ... It is all too frequent that a wrong evaluation is made of what a talented player can achieve. ... Most players have the potential for a certain level; once they have reached it they can only make further progress with a great effort. ... anyone who is unlikely to attain a high playing strength should on no account turn professional. ... Anyone who does not meet these top criteria can only try to earn his living with public appearances, chess publishing or activity as a trainer. But there is a lack of offers and these are not particularly well paid. For jobs which involve appearing in public, moreover, certain non-chess qualities are required. ... a relevant 'stage presence' and required sociability. ... All these jobs and existences, moreover, have hanging above them the sword of Damocles of general economic conditions. ... around [age] 40 chess players ... find that their performances are noticeably tailing off. ..." - from a 12 page chapter on becoming a chess professional in the book, Luther's Chess Reformation by GM Thomas Luther (2016)
http://www.qualitychess.co.uk/ebooks/LuthersChessReformation-excerpt.pdf
I am 15 years old and have a fide rating of 1656, is it possible for me to achieve a GM title.
P.S: I was 1203 2 years back