http://download.cdn.mozilla.net/pub/mozilla.org/mobile/releases/26.0/

After opening dis given link.. 4 folders are showing.. which one i select?

Find more info on: Mobile/Platforms/Android

It suggest that you should download from: Edit: Same link but on CDN: http://download.cdn.mozilla.net/pub/m.../multi/

FTP link from Wiki: https://ftp.mozilla.org/pub/mozilla.o.../multi/

But it depends on what processor type your phone have. If you don't know search for your phone on Wikipedia and you will probably find.

sumitsingh8084, it depends on what kind of cpu your phone or tablet has.

android/ is for ARMv7 devices
armv6/	is for well ARMv6 devices
android-x86/ is new as Firefox 26.0 is the first Release that supports the Intel x86 cpu.

Also please do not link to the ftp if possible as it is not mirrored or load balanced.