Rinse the sticky rice thoroughly in a fine-mesh sieve and drain well.
In a large bowl, soak the rice in enough water to cover it by about 1 inch for at least 4 hours, or overnight.
Drain the rice and transfer it to a saucepan. Add 1 1/2 cups water and salt, and stir to combine.
Bring the rice to a boil over medium heat. Once it starts boiling, reduce the heat to low and cover the pot with a lid. Cook for about 15-20 minutes, or until the water has been absorbed and the rice is cooked through.
While the rice is cooking, prepare the bamboo sections. Rinse them thoroughly and dry them off with a towel. Cut off one end of each bamboo section to create an opening.
Once the rice is cooked, remove it from the heat and let it sit for 5-10 minutes.
Spoon the cooked rice into the bamboo sections, filling them about 3/4 of the way full. Use a spoon to pack the rice down firmly, but not too tightly.
If using, wrap small pieces of banana leaves around the open end of each bamboo section to cover the rice and prevent it from drying out during the cooking process.
Place the bamboo sections in a large pot or kadhai with enough water to cover the bottom. Make sure the open ends of the bamboo sections are facing up.
Cover the pot with a lid and steam the rice over medium heat for about 30-40 minutes, or until the bamboo sections are tender and the rice is cooked through.
Remove the bamboo sections from the pot and let them cool for a few minutes before opening the ends. Use a knife or scissors to cut the banana leaves, if using, and carefully remove the sticky rice from the bamboo sections.
Serve the bamboo sticky rice hot with your favorite curry or chutney.
Enjoy your delicious Assamese-style bamboo sticky rice!