How the heck can I unlock or bypass atavition lock I bought phone with no info and its lock

No such thing. Activation Lock is security protocol with Apple products. Only the person who put "activation lock" on your iPhone 6S can remove it. If you cannot return it to seller for refund, you got "BURNED!"

You don’t.

You were scammed with a phone that is probably stolen property. Unless you can provide legitimate and irrefutable proof it is legally yours, nobody can help you. Not Apple and much less us who are regular users like you.

Turn it over to the police and maybe they will catch the perp and recover some money. But don’t get your hopes up.