Welcome here are some resources from where you can download the latest STOCK ROMS for your Galaxy Young GT-S6312, first here is some info about the stock roms
What is a Stock ROM?
Stock ROMs are the ones which come by default in Android phones or tablets. These are customized versions of Android done by mobile companies to make their devices unique in looks and features.Warranty
Stock ROMs doesn't void your warranty. One of the biggest reasons that people don’t go for Custom ROMs is warranty. Most of the companies prohibit rooting your Android phone or installing a custom Android version – and if you do so, then you can void/lose your warranty.
Premium Apps
Stock ROMs usually come with loaded premium apps which are built by mobile companies to attract customers. These apps can be anything like music players, widgets, live wallpapers, etc. Premium apps are provided to enrich the user’s experience of the customer. These apps differ from one mobile vendor to another and sometimes, even from model to model – more or better apps as the price of the device goes high. For example, Sony Xperia phones have TrackID which can be used to get information about an unknown playing music; Samsung Galaxy S3 has S Voice, a virtual assistant app just like Siri (available in iPhone 4S); etc.Premium Features
Android in original form is cool, but mobile vendors hardly think so – they try to improve it in terms of features and looks. Stock ROMs comes with lots of premium features which are not available in Custom ROMs (at least not for free). These features include custom home screen or launcher or app drawer, e.g., Sony Xperia phones have TimeScape UI whereas Motorola phones have Blur UI. For example, most Android phones come with keyboard with Swype feature using which you can type a word with a single tap on the touch screen by just swiping your finger across each letter of the word and keyboard automatically guess the correct word
Trust for Security
May be it feel strange but one can easily trust Android operating system sold by a reputed company. You can be sure that it does not contain any backdoor, malwares, spywares or other malicious tools. I’m not saying you can’t trust Custom ROM but it’s just that many people take their privacy on top of all other things – you can easily trust a reputed company you know but how can you trust a software or source code of unidentified origin or developer.
INU VS INS
if you are from India there will be two version of Roms INU and INS, these are product code, AKA region code.You can check it on Your device's salesbox or through kies. there is no major difference between INU ans INS Roms. the only thing is if You are on INU region you won't get OTA update of INS region release.same with INS.
Checking on Sales Box
Checking on Kies
just connect your phone to kies and it will show you the product code
Download
Some Sites which hosts the Stock roms, you can use any of the them to download,just open the links and select your country, my personal favorite is SAMMOBILE but you have to make a account to download from SAMMOBILE,
