@Aashna yes the failed graft will survive no doubt. It has new growth from the base plant so all is good.
If you really feel that your rootbound plant needs to be repotted now you can do what is called "potting on". This consists of gently removing the plant from its existing container without disturbing roots or soil and simply putting some new soil in the bottom of a larger container, setting the plant with undisturbed root-ball in the pot and then filling new soil around the edges. This allows you to repot without causing the plant any stress. To remove the plant from its existing pot without damaging the root-ball you need to slide a thin utensil like a butter knife down along the inside edge of the existing pot all the way to the bottom. Keep the tip of your tool as close to the edge of the pot as possible to avoid damaging roots. Don't try to run it around from there but withdraw the blade straight back out. Then press the knife down again adjacent to the previous spot and withdraw it. Continue this until you reach the spot where you started. Then grasp the pot by its edges and while supporting the plant so that it won't fall out on the floor turn it upside down and give it a good shake to loosen the bottom. This might require a second set of hands to gently tug the plant.
I think that covers it all.
