If you are a Samsung Galaxy S3 Mini I8190 user and already updated your phone with Android 4.1.2 Jelly Bean, and want to root the same check this one. Full credits go to the XDA Developer, who has come with this procedure.
1.First, check the device model number, applying this procedure on any incompatible device may brick your phone. So, check them by navigating to the path Settings > About Phone.
2.After that install the USB drivers for Samsung Galaxy S3 Mini on your computer.
3.Next backup all your data with the help of backup applications.
4.Then make sure your phone was factory unlocked and not locked to any particular carrier.
5.After that check the battery percentage level of your phone, in case it is less than 75% charge them fully.
6.After that enable the USB debugging option on your phone by following the path Settings > Developer options.
CWM/TWRP, SuperSU, Odin 3.07 (Downloading links are available in this page under this title)
Disclaimer : Follow the given below procedure at your own risk. If anything goes wrongly on your device I would not be held responsible/liable.
Steps to install CWM/TWRP recovery on Samsung Galaxy S3 Mini I8190 smartphone:
1.First extract the Odin 3.07.zip file using Winrar or Winzip or 7-zip or by using any other extracting tool.
2.Then copy the SuperSu.zip file to the external SD card of your device.
3.After that switch OFF your phone and allow it to boot into the download mode. For that, you need to press and hold volume down button, home button, and power button simultaneously until you see a construction Android robot with a warning triangle appears on your screen.
4.Then press the Volume Up button, now it will enter into the download mode.
5.Next run the Odin on the computer as the administrator.
6.Then connect your phone to the PC using USB cable while it is in the download mode.
7.Then wait until the Odin detects your phone, once it has been detected, the ID: COM box will turn to light blue with the COM port number. You can confirm the detection of your phone by saying “Added” message.
8.In case, you do not get the added message, re-install the USB drivers or changing the USB port on your computer.
9.Now, in Odin, tap the PDA button and select the CWM/TWRP Recovery .tar.md5 file. Check the F.Reset time and Auto Reboot checkboxes are selected. At the same time, check the repartition option is not selected.
10.Then double-check and tap the start button in Odin. Now, the installation process will start in your phone.
11.Once it is finished, your Galaxy Mini will get a restart, and you will see a PASS message at the top of the ODIN.
12.Now, unplug the USB cable from the computer and disconnect your phone.
Procedure to root Samsung Galaxy S3 Mini I8190 smartphone:
1.First reboot the device into the recovery mode by pressing and holding Volume UP button, Home button and Power buttons simultaneously.
2.In CWM recovery, select “install zip from SD card” and then select “choose zip from external SD card”.
3.After that go to SuperSU.zip file that you have copied earlier and confirm the installation process by selecting the “yes” option.
4.Once the process was finished, return to the main recovery menu and select the “reboot system now” option.
That’s it! Now, you have rooted your phone successfully, congrats!