class DataFix {
    String registrationNumber {get; set;}
    String minBillDraft {get; set;}
    String minBillCorrection {get; set;}
}

StaticResource minBillFixJSON = [SELECT Body FROM StaticResource WHERE Name = 'minBillFixJSON' LIMIT 1];
String minBillFixJSONAsString = minBillFixJSON.Body.toString();
List<DataFix> dataFixesList = (List<DataFix>)JSON.deserialize(minBillFixJSONAsString, List<DataFix>.class);

Map<String, List<String>> regNumToMinBillMap = new Map<String, List<String>>();
for (DataFix i : dataFixesList) {
    regNumToMinBillMap.put(i.registrationNumber, new List<String>{i.minBillDraft, i.minBillCorrection});
}

List<Quote> qotToUpdateList = [
    SELECT Minimum_Bill_Draft__c, Minimum_Bill_Correction__c, Opportunity.Contract.Registration_Number__c
    FROM Quote
    WHERE Opportunity.Contract.Registration_Number__c IN :regNumToMinBillMap.keySet()
];

for (Quote qot : qotToUpdateList) {
    qot.Minimum_Bill_Draft__c = Decimal.valueOf(regNumToMinBillMap.get(qot.Opportunity.Contract.Registration_Number__c)[0]);
    qot.Minimum_Bill_Correction__c = Decimal.valueOf(regNumToMinBillMap.get(qot.Opportunity.Contract.Registration_Number__c)[1]);
}
update qotToUpdateList;