Anyways my download speeds keep fluctuating. Sometimes it is 15 mbps/ 1.87 MBps or sometimes it goes as high as 65 mbps/ 8.5 MBps. But my speedtest results are always the same at around 93 mbps / 11.6 MBps.
I just wanted to know why the difference between speedtest and actual downloads.
that is pretty normal when downloading torrents, esp public ones. Try direct download links from some server which can match your connection speed or a private tracker with many seeders. Anyway from my experience torrent download speeds fluctuate a lot.