Yes, you can absolutely cook rice without salt and season it later. Adding salt during cooking is primarily for flavor, not for the cooking process itself.
Cooking rice without salt is a common practice, especially when you want to control the sodium content of your meal or plan to use the rice in a dish with a sauce or other ingredients that already contain salt. The rice will cook perfectly fine in plain water. The salt doesn't affect the texture or cooking time significantly. Simply cook the rice according to your preferred method (stovetop, rice cooker, microwave) using the appropriate water-to-rice ratio. Once the rice is cooked and fluffy, you can then season it to taste with salt, soy sauce, herbs, spices, or any other desired flavorings. This gives you greater flexibility in adjusting the final flavor profile of your dish.
If you're using a rice cooker, remember that some models have a 'keep warm' function. If you've seasoned the rice after cooking, stir it well before leaving it on 'keep warm' to ensure even distribution of the seasoning and prevent clumping.