Chat app

Question

How to develop a chat forum wherein close buddies only can confer.. Max limit being just 100 pers

Answer 1

There are many options available online for that type of thing, just search create a forum.
Or use Slack or an alternative.
But if you really want to build your own, you'll have to learn HTML CSS and PHP and database.
If you are ready for the task, follow this tutorial.
https://code.tutsplus.com/tutorials/how-to-create-a-phpmysql-powered-forum-from-scratch--net-10188