You are filing in a country where tourist visas are basically an automatic No. If his family has proof of traveling to other countries and returning. Chances are higher. If his parents are elderly, they have a higher chance of approval.
how old is the son? Tourist visas are more likely approved for 10 and under than someone who is a teenager.
It is important to obtain as much information for yourself as JA tends to focus on rumors and hearsay about immigration.