ROI were virtually assured of the trophy after scoring 296 for 4 in the second innings — an overall lead of 413 runs.
Yesterday, ROI increased the overall lead to a mammoth 506, declaring their second stint at 389 for 5, with Ambati Rayudu remaining unbeaten on 156.
The match was always heading for a draw unless Mumbai were bowled out. But the 40-tim Ranji champs instead cruised to 160 for 4 with Jaffer scoring an unbeaten 101 before the game was called off by mutual consent during the last hour of play.
Brief scores: Rest of India 526 & 389/5d
Mumbai 409 & 160/4 (54.0 overs)