For this you have to follow some steps. From the home screen-
1: Pull down the notifications bar and tap on the settings icon
2: Select "Mobile Data". Some phones you'll tap on "More" first, then "Mobile Networks"
3: Open up "Access Point Names"
4: Tap on "Menu" (the three vertical dots) and select "New APN"
In the new APN fields, put in the following:
Name: SIMPLE Mobile
APN: simple
MCC: 310
MNC: 260
APN type: default,supl,admin,mms,hipri
Leave all other fields blank or unchanged.
5: Press Menu and select "Save"
6: Press the back step button to go back to the APN list and tap the button of you newly created SIMPLE Mobile APN to select it as default.
7: Restart your phone and you're set!
For any other support You can visit in Samsung India site in its support option.