Williamson to lead, Boult returns as New Zealand announce 15-member squad for T20 World Cup on Monday.
Chennai Super Kings move to third on the points table but are tied with four other sides on ten points.
A fiery 41-ball century by Will Jacks and Virat Kohli unbeaten 70 runs helped Royal Challengers Bengaluru to a 9-wicket victory over Gujarat Titans.
The unbeaten blistering 121-run partnership between Sanju Samson and Dhruv Jurel powered Rajasthan Royals to a 7-wicket victory over Lucknow Super Giants on Saturday.
The series finished 2-2, with Pakistan winning the fifth and final T20I at Lahore on Saturday.
Chasing a big target, MI were in the hunt courtesy Tilak Varma, Hardik Pandya and Tim David, but they fell short in the end.
Jonny Bairstow and Shashank Singh power-hitting display propelled PBKS to chase down the highest total in 8-wicket win.
Rashid nearly took Titans home in pursuit of 225 but Mukesh held his nerve to defend 19 off the last over
Lucknow Super Giants beat the Chennai Super Kings for the second time in the space of five days.
Royals signed off from the Jaipur leg of their campaign with a seventh win in eight matches to cement their table-topping status.
