(adsbygoogle = window.adsbygoogle || []).push({}); How can we jailbreak PS3 firmware 4.75 and what are drawbacks for it. And can I play online like on the non jail broken PS3.

I don't understand what you mean, Be more clear?

there is no 4.75 jailbreak. Period

I mean that I need help to jailbreak and I need help to install mod menus and stuff. And will I be able to play online if I jailbreak

You can't jailbreak 4.75 :p

Ok how to downgrade then without E3 flasher and can I play online if I jailbreak

the only way to downgrade and jailbreak is with a hardware flasher

or find a PS3 already on 3.55 and begin your hacking life my friend

Hahah lol

You would need to downgrade to 3.55 OFW with an E3 Flasher. If you are new to modding and CFW etc., I would recommend that you buy a PS3 on 3.55 OFW or one that is pre-jailbroken. Using an E3 Flasher involves you taking your PS3 apart and downloading files. If you do not know what you are doing, it could brick your PS3.