Substituted summons when the regular summons are returned

The Order V rules deal with the summons and the rules surrounding it. Rules 9-16 address how a summons has to be served. Rule 9 says that summons should be served by the proper officer or his subordinate. Rule 10 prescribes the mode of service viz. by delivering or tendering of duly signed and sealed summons. Although Rule 12 says that summons has to be made in person, rule 15 provides if the defendant cannot be found and also has no authorised agent then service of summons on an adult male member of defendant's family would be considered as good service. The passing of a substituted summons is restricted to certain situations, as per rule 20 a court can only pass an order for substituted service when it comes to the conclusion that, either the defendant is keeping out of the way for the purpose of avoiding service or for any other reason the summons cannot be served in ordinary manner. Now how is it determined that a person is avoiding the summons? The same is provided for in rule 17 and 19. If the defendant or any other person liable to receive summons under the law refuses to receive the same or if the serving officer, despite exercise of due diligence cannot find the defendant or his agent or person liable to accept summons, then he would affix the copy of summons on the house or place of work of the defendant and return the original summons to the court with the endorsement about the circumstances in which the affixation of summons has been made. In this case it is said that the defendant is out of station and not actively avoiding summons so substituted summons may not apply. Since summons is not duly served ex parte is not an option

You have explained the whole process of service of Summons.Thank you very much for the detailed reply.