Which is your mobile ?? it's model ? Vendor ?? you get OTA updates in your country region only if your vendor developed New version for your handset.
for Ex. In the case of Samsung devices they provide OTA updates for newer android verions(KK,Lollipop) mainly for flagship models(S4,S5,Note 3,Note 4 ect) and sometimes for other models(Note 3 Neo,Note 2 etc) also.
In my case now am using
Samsung Galaxy Note 3 Neo, when I bought this device it android Version was
4.3(Jelly Bean) and my phone's country region was
4.4.2 (KitKat) update for my phone model only for INDIAN Region Phones. i.e. the device in other region wont get this update via OTA.
But in this case we can update new firmware (OS) manually without affecting
Warranty with the help samsung firmware flashing application called
ODIN, To do this we need to download latest
firmware from SAMMOBILES
just see the below image of
firmwares for different
Samsung Galaxy Note 3 Neo SM-N750 Model
See How to flash Samsung Stock Rom using Odin.
If device vendor not released any OTA or Firmwares then you need to go for
is an aftermarket firmware for a number of cell phones based on the open-source Android operating system. It offers features not found in the official Android based firmwares of vendors.
see your device is listed here or here.
List of devices supported by CyanogenMod
still you cant find a ROM or Firmware or Latest android version for your device you must look into xda-developers.com,
The site's main purpose is discussion, troubleshooting and development for Android, Windows Phone, WebOS, Ubuntu Touch, Firefox OS and Tizen phones. The site also offers Windows Mobile and Android users general information about devices, ROM upgrades, technical support, Q&A, and reviews of device applications and accessories. Separate forums exist for each model of phones manufactured by Sony, HTC, Samsung, LG, Motorola, and many others. Forums are also available for tablets and many other devices.
Read more about
xda-developers from here
If you have time, patience then try to know CREATE OWN ROM FOR ANY ANDROID DEVICE