It is permissible to exit Ihram if one is prevented from completing Hajj; It is permissible to perform Qiran and the pilgrim performing Qiran should perform just one Tawaf and one Sa'i

Nafi' reported that 'Abdullah b. Umar (Allah be pleased with them) set out for Umra during the turmoil, and he said: If I am detained (from going to) the House, we would do the same as we did with Allah's Messenger (ﷺ). So he went out and put on Ihram for 'Umra and moved on until he reached al-Baida'. He turned towards his Companions and said: There is one command for both of them. and 1 call you as my witness (and say) that verify I have- made Hajj with 'Umra compulsory for me. He proceeded until, when he came to the House, he circumambulated it seven times and ran between al-Safa' and al-Marwa seven times, and made no addition to it and thought it to be sufficient for him and offered sacrifice.