Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.
We do not know any evidence related to reading Surah Yassin a number of times. But rather, this is an innovation as Imam Al-Shatibi stated in Al-I’tissam saying: ‘Among these innovations is to adhere to the performance of given actions of worship at given times the criteria of which is not laid down by Shariah, for example fasting the day of Mid-Sha’ban and performing some special prayers during the night of the same day.’
A Muslim has to implore Allah by His good Names and Attributes and supplicate Him with humility and submission at all times, mainly at times and places where the supplication is accepted, so that Allah may fulfill his needs. Allah Says (interpretation of meaning): {And when My slaves ask you (O Muhammad) concerning Me, then (answer them), I am indeed near (to them by My Knowledge). I respond to the invocations of the supplicant when he calls on Me (without any mediator or intercessor). So let them obey Me and believe in Me, so that they may be led aright.}[2:186].