How can u get my cousins baby out of foster care I haven't seen this cousin for 15 years but her family contacted me to get him well the case worker said he was already place in foster care and I can't get him is this true ? And if so is there anything I can do to get him he's 6 now old

You don't just do it... you have to go through the courts, as they placed the child into the foster care system, only they can remove them.

Hire a lawyer... its not a do-it-yourself thing.

Ok yeah I know I would have to hire one but just want to make sure I would have a chance if I fought

You have a chance... but I can't guess how much. My guess is they would rather have a long term or permanent placement than the foster care one assuming you can provide evidence you can provide a good and stable home to their satisfaction.