In the Instant Pot, combine rice, sugar, salt, and milk.
Select Sauté function and bring contents to a boil, stirring constantly to dissolve sugar. As soon as the mixture comes to a boil, cover and lock lid in place.
Select Manual or Pressure Cook function on the Instant Pot and adjust to low pressure. Set cooking time for 16 minutes.
While rice is cooking, whisk eggs with half and half and vanilla. When beeps sound, turn off pressure cooker, wait 10 minutes and then use a quick pressure release. Carefully remove the lid. Stir the rice in pot.
Stir the egg mixture in to the pot. Select Saute and cook uncovered until mixture just starts to boil.
Turn off pressure cooker. Stir in raisins.
Serve immediately, or pour into servings dishes cool then chill. (Pudding will thicken as it cools, so you may want to add a little extra half and half if you’re serving it cold.) Enjoy!