is there neccessory to take ghusal after drinking alcohol

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu 'alyhi wa sallam, is His slave and Messenger.

First of all, a person who consumes intoxicants is obliged to repent to Allaah because consummating intoxicants is an abominable and a grave major sin. Ibn ‘Umar narrated that the Prophet, sallallaahu ‘alayhi wa sallam, said: “Whoever drinks alcohol, in this worldly life, and he does not repent from it, it will be forbidden for him in the Hereafter.” [Al-Bukhari and Muslim]

It is also confirmed that he, sallallaahu ‘alayhi wa sallam, said: "Any intoxicating drink is forbidden, and Allaah promises those who drink it to make them drink from the sweat of the people of Hellfire…."  [Muslim]

Therefore, a person who consumes intoxicants is immediately obliged to repent to Allaah and stop consuming it.

As regards to Ghusl (ritual bathing), it is not obligatory for a person who consumes intoxicants to perform Ghusl because of his consumption of it because consuming intoxicants is not one of the matters that mandate Ghusl. However, it is an obligation to wash the body or clothes that are stained by it because intoxicants render them impure according to the view of the majority of scholars .

For more details, please refer to Fatwa 82245.

Allaah Knows best.