If you want to submit a WhatsApp group link to a directory and have it stay up, make sure it opens, is not already listed, sits in the right category, lets people in without waiting, and suits a general audience. Most rejections come from one of these, and none of them is mysterious.
Directories are not out to turn you down. A reviewer opens your link, sees what a visitor would see, and decides whether it helps the next person who clicks it. Your job is to make that check boring.
What a reviewer checks when you submit a WhatsApp group link
The sections below say more about each one, because the fix depends on the platform.
The link has to work today
Dead links are the most common rejection. A link breaks when the group's admin resets it, when the group is deleted, or when a typo crept in while copying. WhatsApp links do not expire on a timer. They stop working because someone reset them, often by accident while changing group settings.
Test it again on the day you submit, not the day you created the group, because a reset in between is common. Test the link the way a visitor would. Open it in a private browser window, or send it to a friend whose account is not in the group and ask what they see. If it works only for you because you are already a member, it has not been tested at all. Telegram and Discord behave the same way, and the Telegram FAQ and Discord's page on joining a server show what a working invite looks like.
Duplicates, and how a reset link causes them
Search the directory for your group's name before you submit. If the group is already listed, the reviewer rejects the new entry, and resubmitting does not help. A reset link can also make an old listing look like a different group, because the address changed but the group did not. If you run the group and only the address changed, say so if the form gives you room to. Where the directory lets you report a dead link on the old entry, do that instead of making a second one.
Pick the category that matches the group's main purpose
A group has one main purpose even if it talks about many things. A job-alert group belongs with jobs, a group that shares exam notes belongs with exams. When two categories seem to fit, choose the one a stranger would browse. Read the category names on the form before you choose, and pick the one a stranger would look under.
Name and description matter too. Write them for a person. All capitals, strings of emojis, a phone number in the title and keyword lists read as spam, and spam gets rejected faster than anything else.
Approval links, and why reviewers cannot get in
WhatsApp can require admins to approve new participants, and Telegram invite links can require approval too. For private groups that is a sensible choice. For a directory listing it causes a problem, because the reviewer clicks Join, sees a waiting screen and cannot confirm that the group exists. The visitor has the same problem, and many directories reject these links for that reason.
Rules differ from one directory to the next. If you need screening, one workaround is to turn approval off for the review, then rely on rules and a quick check after joining. Do not resubmit repeatedly while you wait, since each attempt can create a duplicate.
Content that does not belong in a general category
Adult content is the standard example. Directories either refuse it or keep it away from sections anyone can browse, so putting it in a general category gets the entry rejected. The same applies to groups built around guaranteed returns or "easy income" promises, which are the pattern described in the signs a group link is not what it claims. Reviewers learn that pattern quickly.
Where to submit
Each platform has its own submission page. For WhatsApp groups and channels, use the WhatsApp submission page. Telegram groups and channels go through the Telegram submission page, and Discord communities through the Discord submission page.
If an entry is rejected, read the reason before touching anything, fix that one thing and submit again once. Sending the same link repeatedly without a change only makes the reviewer's queue longer and your entry less welcome. Get the link tested, the category chosen and the description written before you open the form. Doing it in that order saves a rejection.
If you only do one thing
Open your link from a different account, then submit it. A listing is one piece of getting people into a group, and the rest is covered in getting your first members into a new group. How the links work behind all of this is in how group links work.