How to rejoin a group message

Welcome to the Apple Support Communities!

I understand you removed yourself from a group chat by mistake, and would now like to rejoin the group. If this is an iMessage group, all you need to do is ask one of the other goup members to add you to the conversation. See the resource below for more information. I've highlighted some key information here for you. Click on the link for complete details.
Send a group message on your iPhone, iPad, or iPod touch

Add or remove someone from a group conversation

Anyone in a group iMessage can add or remove someone from the conversation. You can remove a person from a group iMessage that has at least three other people. You can’t add or remove people from group MMS messages or group SMS messages.

Add a person

1. Tap the group conversation you want to add someone to.
2. Tap , then tap Add Contact.
3. Enter the contact information for the person you want to add. Then tap Done.

Take care.