Immediately leave the group and block the admin. Then, change your WhatsApp privacy settings to "My Contacts" for group additions.
If you cannot find a reliable , consider these alternatives for similar content:
Many Kerala Vedi groups maintain a presence on Telegram (which allows larger audiences). These Telegram channels post daily updated WhatsApp group links. Search for keywords like "Kerala Vedi Telegram" or "Sanghi Malayalis Telegram" on Telegram's search bar.