i got a Over The Air update for 4.2.2 on my Samsung Galaxy S2 Plus. I'm in India. After installing the update my phone rebooted and now it doesn't start. it only loads and shows the samsung's logo. What should i do now?
Firstly, it's not an official update.
Secondly, to fix this error you need boot your phone into recovery mode (press Power + Volume Up + Home). After that, move the cursor down to "Wipe data/factory reset" and select "Ok" (yes to all). Then select "Wipe cache partition" and "Ok" (yes to all). Finally, select "Reboot system now".
Note: OP states that he is in India and is using the Samsung Galaxy S2 Plus with the model GT-I9105P. Based on my research, the model GT-I9105P is released for European and Chinese countries (China, Taiwan and Hong Kong)
I think you should be using the Samsung Galaxy S2 Plus with the model GT-I9105 because only this model is released for use in India. I think you bought or import this model from somewhere else?
For answers suggesting that they didn't receive OTA update notification are probably because "Auto update check" isn't enabled. Both Samsung Galaxy S2 Plus with model GT-I9105 and GT-I9105P have been released with updates containing Android 4.1.2.
For answers suggesting that it is "not an official OTA update by Samsung", refer to the link below because you can clearly see that the OTA update has been released for the Samsung Galaxy S2 Plus for over 6 years!! Released on 21 October 2013. Since OP doesn't mention that he is using a Custom ROM of any sort, he is using a vanilla Android 4.1.2 with Touchwiz UI that is factory installed "officially" by Samsung
By checking this website https://samfrew.com/model/GT-I9105P it clearly states that Android 4.2.2 has been released for Samsung Galaxy S2 Plus for over 6 years!!!
Since OP said that his friend has helped him to reinstall Android 4.1.2 (I'm assuming that his friend helped him to install Android 4.1.2 by using Odin 3 and flash the phone clean, or "staring everything from zero / the way it came to you from the factory")
You can safely update to Android 4.2.2 as your phone is now in a "clean" state which means that apps or system services causing the phone to disrupt the update process previously will be gone because your phone has been formatted by your friend.
If you install any mods such as Root or Xposed previously, this is the main reason why the update fails. Root and Xposed solutions disrupt the update process by modifiying the "system partition" to make sure that the apps work properly. It doesn't care about you updating your phone because the main reason "Root" exists is because it is used to modify "system" files.
Do not install any Root or Xposed solutions if you plan to update your phone. Uninstall them before updating your phone or it will brick your device, rendering it unusable