I understand that when dislike in marrigae is high then marriage is no longer valid. please clarify what is defined as dislike and what implications are there for the nikaah if dislike is high.

Rasulullah (Sallallaahu Álayhi Wasallam) said, 'The most detestable among the permissible things in the sight of Allah is divorce.' If there is a dispute between husband and wife, they should first try to resolve it between themselves, failing which, Allah says, 'Two persons representing the husband and wife respectively should arbitrate and amicably resolve the dispute.'

As far as possible, a divorce should be avoided. However, after exhausting all avenues of reconciliation, as a last resort, Allah says, 'Keep with principle or release with principle'. If the husband and wife cannot fulfill their respective duties to one another, then instead of committing a sin of violating one another's rights, they should separate. The husband should release his wife with principle by giving her divorce. In such a situation, if a wife seeks for a divorce, she will not be sinful. If the husband refuses to divorce her, she may make Khula, i.e. offer to repay her dowry to him in lieu of him granting her the divorce. If the husband is still spiteful and withholds the divorce, the woman may contact the Úlamaa (scholars) of her locality who are well versed with judiciary principles of Islam requesting them to annul the marriage.

and Allah Ta'ala Knows Best

Mufti Ebrahim Desai