As you have already initiated proceedings against the tenant's son under S. 138 NI Act, bailable warrants would have been already issued, if the tenant's son had failed to appear before the court , despite of the service of summons.
If he doesnt appear on the next date of hearing, non bailable warrant would be issued against him.
You should also consider file a suit for eviction of tenant on grounds of non payment of rent.
In this way youll get both the rent as well as the tenant would be evicted.