Using a stand or hand mixer, combine cream cheese and granulated sugar until fluffy.
Add eggs, one at a time mixing each until combined.
Add lime juice, lime zest, margarita mix and sour cream. Mix on medium speed until smooth. Do not overbeat.
Pour into crust. Run a fork through the filling several times to remove air bubbles.
Cover with foil, sealing edges. Poke a small hole in center of foil to allow steam to escape.
Add 1½ cups of water to bottom of Instant Pot.
Set cheesecake pan on trivet that comes with your pot and lower into Instant Pot.
Set on manual high pressure for 75 minutes.
When time is up, turn Instant Pot off and allow the cheesecake to remain in pot for 15 minutes.
Manually release any remaining pressure and remove cheesecake. Remove foil and check for doneness. If the cheesecake jiggles only in the center, it is done. If it jiggles overall, replace foil and cook for an additional 10 minutes.