Hi Faseeh16,
I understand you're having trouble with MMS messages. I know it's a great feature to keep in touch with your groups, and I want to help.
Check out this article that helps explain the difference between MMS and other messages:
About iMessage and SMS/MMS - Apple Support
If this is happening consistently when sending MMS group or picture messages, you'll need to make sure you're in an area that has strong data signal of 3G or better. Make sure you have cellular data enabled and MMS enabled in Settings > Cellular and Settings > Messages.
If you continue to experience an issue, you'll want to contact your carrier for further assistance with MMS.
Thanks for using the Apple Support Communities.