Telegram is a popular instant messaging app that allows users to create and join groups to chat with multiple people at once. While many Telegram groups are public and open for anyone to join, there are some groups that have limits on the number of members that can join. These groups may also have certain restrictions on who can join, which can make it difficult for some users to gain access. Here are some reasons why you may not be able to join an unlimited Telegram group:

Group size limits: Some Telegram groups may have a maximum number of members that can join, which can be set by the group administrator. Once the group reaches its maximum size, it may not be possible for new members to join. This is particularly true for private groups or those that require an invitation to join.
Group restrictions: Some Telegram groups may have certain restrictions on who can join. For example, the group may require members to be a certain age, from a specific country, or have a certain level of expertise in a particular field. If you do not meet these requirements, you may not be able to join the group.
Blocked by the group administrator: If you have been blocked by the group administrator, you will not be able to join the group. This can happen if you have violated the group's rules or if the administrator has identified you as a spammer or troll.
Inactive group: Some Telegram groups may have become inactive, with little to no activity from the members or the group administrator. In such cases, it may not be possible to join the group, or even if you do, you may not be able to participate in any meaningful way.
In conclusion, while many Telegram groups are open for anyone to join, some groups may have limits on the number of members or restrictions on who can join. Additionally, if you have been blocked by the group administrator or the group has become inactive, you may not be able to join or participate in the group. It is important to respect the rules and guidelines of Telegram groups and to engage in meaningful and respectful interactions with other members.