Yes I made a detailed video on it.
74 days may be BUT Honda says it starts from Cheque/Pay-order Clearance Date, so calculation may vary by a few days
It does not matter what you paid, its the Official Partial Payment based on which penalty amount is calculated. Full payment is irrelevant. Kibor+3 is calculated on Partial (Official Partial amount is 10 Lacs or 12 Lacs? Please confirm). Please also note, company calculates Kibor+3 on Initial Amount AFTER deducting 17% tax first.
Use this video as reference for calculation and you will get much much nearer to the 23.5k figure provided by company.