Slow Cooker: Place beans, Rotel, taco seasoning, dry ranch dressing mix, and chicken into bottom of slow cooker. Place lid on top and cook on low for 8 hours or high for 4 hours. Take lid off slow cooker and shred chicken. Serve soup in bowls with desired toppings.
Instant Pot: Place beans, Rotel, taco seasoning, dry ranch dressing mix, and chicken into Instant Pot. Place lid securely on and close. Move valve on top to "sealed". Set to manual, high pressure, for 15 minutes. Once done, do a quick release. Remove lid and shred chicken. Serve in bowls with desired toppings.