Arbitration In Agreement To Sell Of Property Dispute

Agreement to sell & purchase of property advance paid. Balance to be paid within 6 months on the execution of sale deed. Arbitration clause with Sole arbitrator. 2-3 extensions but did not execute the sale deed in next 3 years. In a joint meeting with mediator, the seller informed that due to some family problem, he will not be able to execute sale deed and requested to cancel the ATS and agreed to refund the advance with the penalty. He requested not to go for arbitration or to court. The seller also requested to clear the dues in 18 monthly installments due to his financial difficulties due to lockdown. The settlement was verbal. He issued 6 post dated cheques in advance. Two cheques were honoured; two bounced but did not make payment. 138 case was compounded by the seller. The buyer filed a recovery suit for balance amount. Seller applied to invoke arbitration. He had sold the property to third party before settlement. Complaint filed U/S 156-3 for Fraud. Can he ask for arbitration?