Reference: http://www.alfawzan.af.org.sa/node/15758
Question: What is the ruling of reading Soorah YaaSeen over the deceased after his burial?
Response: The hadeeth about this is not confirmed [to be authentic], and it is [therefore] not recommended to read Soorah YaaSeen over him. However, that which is recommended is to instruct him [whilst he is on his deathbed] to say the shahaadatayn – every time you notice he is receptive – instruct him, but do not be so repetitive that it becomes burdensome for him, rather gently prompt him.