Admission withdrawn by college after taking fee, can action be taken ?

My daughter applied for admission into an Indian University undergrad program through their multi-step admission process involving filling application form details, certificates and annexures; then shortlisted for Essay writing, Interview & Written Aptitude Test. She got through and received an unconditional offer with request to pay initial deposit and send acceptance, which she did. Now on receipt of her class XII results (IB board) where she has passed but with low marks, they are withdrawing the offer, stating that they only admit students who achieve beyond a certain level of marks (i.e. IB Diploma). This condition was never stated in their 'unconditional' offer nor anywhere in their admission policy, which states that 'the higher of the Written Aptitude Test or board marks will be considered' and 'for IB students only students enrolled under IB diploma are eligible to apply'. She fulfils both criterion, so we need legal advice to put it across to Univ and reverse.