i thought it could be one of the xposed modules which might be interfering so i unrooted my phone and put it back to stock. The wifi signals were fine for a day or so and i am now facing the same problem again.
I downloaded the Wifi Analyser app from the play store to check if there is any interference from other routers in the vicinity. I have changed the channels multiple times but to no avail. At the same time my laptop & desktop connects fine to the router.
I am currently running stock 4.4.2 build # KOT49H