If TWRP is not your cup of tea you will have to stick with the good old clock work mod recovery for getting new ROMs on your Samsung Galaxy Grand 2 SM-G7102.
Here is how you can download and install it on your phone. Download links are given at the bottom of this post.
1) Install whatever drivers make you happy and make your device connect (i would suggest Samsung ones).
2) Reboot your device in download mode you can use ADB reboot download or the hardware key combo for your device.
3) Load up Odin and uncheck auto-reboot. Uncheck the option RE-PARTITION(important) and select AP/PDA, select the downloaded recovery.
4) Click PDA and select the CWM tar you downloaded.
5) Connect your device in download mode.
6) Click start.
7) When its finished disconnect your device, pull the battery out.
8) Reinsert the battery and use the hardware keys for your device to power directly into recovery mode (this will bypass install-recovery.sh if you are stock).
9) Enjoy having a custom recovery.
CWM for NG4 (4.4)
http://www.mediafire.com/download/dx2mm590clsynzt/CWM-6.0.5.1-mukul.zip
Odin http://shabbypenguin.com/?developer=Tools
And here are the instructions on performing root on Galaxy Grand 2 SM-G7102
Get the file from here and copy it to your device. Then flash it in recovery. Reboot and load up the Super SU file. Then disable KNOX and reboot into recovery. Reflash Super Su and you will be rooted.