May one rely on the opinion that 9 men + a katan holding a sefer torah is a minyan? (For example, right now there are 9 people and if we wait for a 10th to come, we will miss shkia or zman tefilla)
Does the katan have to actually hold the sefer torah in his hands?
If so, what should be done during krias hatorah?
It is very controversial, and many poskim say not to do it any instance. Therefore it should not be done without asking a Rov for each individual case. From those that do allow it, many say that it doesn’t have to be specifically a sefer torah, but a chumash is also good, or even if the sefer torah is on the bimah, and he is holding the Atzei Chaim. Others say that it is a zilzul to give a child a sefer torah to hold, therefore a chumash is better. But again it should only be done with the consent of a Rov for each specific instance.
M:B 55-24, Eishei Yisroel 15-8 in the name of R’ S. Z. Auerbach zt”l, Igros Moshe O:CH 2-18, Chelkas Yackov 1-93.