What will probably happen to Rikki-tikki in the future in "Rikki-tikki-tavi"?

Rikki will probably remain in the bungalow and keep snakes from going into the garden.

Rikki-tikki is glad when he washes up in the garden of the British family. They have a house and a garden full of adventure for him. Rikki knows that being a house-mongoose is a big responsibility, but “every well-brought-up mongoose always hopes to be a house-mongoose some day.” Rikki protects the people from snakes, and they make sure he is comfortable and well-fed.

Rikki has a big task ahead of him, because the garden is inhabited by a pair of cobras and a tiny snake. He has to kill all of the snakes in order for the people to be safe in their house. The snakes know that Rikki is a danger to them, and they put up quite a fight.

Nag was thinking to himself, and watching the least little movement in the grass behind Rikki-tikki. He knew that mongooses in the garden meant death sooner or later for him and his family, but he wanted to get Rikki-tikki off his guard.

Rikki battles Nag and Nagaina, killing the male cobra first and then the female one. He dispatches with little Karait too. Soon the garden is safe from snakes, because he has also killed all of the baby cobras. Rikki knows that his responsibility is not ended, however.

Rikki-tikki had a right to be proud of himself; but he did not grow too proud, and he kept that garden as a mongoose should keep it, with tooth and jump and spring and bit, till never a cobra dared show its head inside the walls.

Even though there are no snakes now, that does not mean there will not be snakes in the future. Rikki has to be constantly alert. With him there on patrol, the snakes will stay away and the family will be safe.