Has it been mentioned in the Quran or Sunnah that there is support for a gathering of people to recite Surah Yasin a specific number of times, after which one of them steps forward to supplicate while the rest raise their hands and say "Ameen" to his supplication?

The Prophet, peace and blessings be upon him, used to gather with his Companions, read the Quran, teach them, and guide them. Sometimes he would instruct some of his Companions to read while he listened. Therefore, if brothers gather, read what is easy from the Quran, ponder over it, and understand it, this is a great good. It is also recommended for those who listen to pay attention. As for repeating specific surahs a certain number of times, or designating a certain number of surahs, or raising hands collectively after the recitation, we do not know of any basis for this in the Sunnah (definition). It is better for each individual to supplicate for himself. The purpose of reading is contemplation, understanding, action, and benefit.