Is it obligatory to renew the marriage contract if the husband expelled his wife and she remained in her family's home for more than two months? And what is the duration of the marriage contract?

The mere act of the wife going to her parents' home by herself or after being expelled by her husband, and staying there for two months or more, does not constitute a divorce. If the husband orders her to return, she is obligated to do so. There is no need for a new contract or reconciliation since no divorce has occurred. This fact must be clarified to the wife and her family, and an attempt should be made to reconcile, seeking assistance from righteous family members, as Allah Almighty guided in His saying: "And if you fear dissension between the two, send an arbitrator from his people and an arbitrator from her people. If they both desire reconciliation, Allah will cause agreement between them. Indeed, Allah is ever Knowing and Acquainted [with all things]." If the problem is not resolved, then recourse should be made to the Sharia (definition) courts. All of this applies if the husband has not uttered the words of divorce; however, if he has divorced her, the matter is different.