I'm unable to see the group name option and add contacts in MMS group for iPhone 12 and iPhone 12 pro max

You cannot add a contact to a group MMS, nor can you name a group MMS. Those features can only be done with iMessage.

See this, Add and remove people in group text messages - Apple Support

And this, Name a group text message on your iPhone, iPad, or iPod touch - Apple Support

Hello Rpbeena and welcome to Apple Support Communities. It appears you are having some difficulty with the group name and add contacts functions in group messages sent via standard SMS/MMS.

These features are only available in groups where everyone is using iMessages.

Cheers.

I have the XR & my husband has the 12 pro Max & neither of us are able to add contacts to group texts. The “add contact” option isn’t there like it used to be. The other people in the text have iPhones & using iMessage. Please help

I did those steps & the option isn’t there like it used to be.

Are you certain that this is a group iMessage? If anyone in the group is not using an iOS device, you cannot do either of the things that you asked. Are responses in the thread all blue bubbles, or are they green bubbles?

I cannot find add contact to a group MMS nor do I see how to name the group on 12 Pro MAX. Frustrating!