Can you drink beer here

There is a designated area for barbecue maybe there allow to drink i don't know

No you can't

There is a designated area on the North Shore where alcohol is allowed.

I did see people drinking.

Not really, no.

So which is it, yes u can bring beer in or no you can't?

Copied and pasted from their website- Outside alcohol is not permitted at Lake Gregory inside or outside the gates. We do however have a Beach Club bar open every Saturday and Sunday from 12-5:30pm.  On Fridays the park is open to the public from 6:00pm to 9:30pm for our weekly Beach club with live music, food and drinks.

No.

Yes