(22-04-2018, 03:08 PM)Faraz Khan Build number : X509-J5800-KK-20150723
Android version : 4.4.2
The firmware for that build number isn't yet available at https://www.hovatek.com/forum/thread-20027.html , only a slighly higher build.
I suggest you first backup your current firmware before attempting to flash anything.
Is your phone rooted?