If a missed masikam is done with the subsequent month’s masikam, two people are seated for the Pitru sthanam. After mentioning both masikams in the sankalpam, ‘tantrena karishye’ is included in the sankalpam.
For example, when 4th and 5th masikams are done together, in the Vishvedeva varnam of Vishnu varnam, ‘turiiya panchamaana maasike tantrena karishye! Turiiya panchamaana maasike shrarddhe vishve devaartham bhavadakshana kartavyaH Vishnu devaartam bhavadakshana kartavyaH’ is recited.
For the two seated in the Pitru sthanam, one must recite ‘turiiya maasikaarte bhavadakshana kartavyaH’ while the second person recites ‘panchamaa maasikarte bhavadakshana kartavyaH’, while seating them.
Likewise, during dattam (giving away an offering/charity), for those who are seated in Pitru sthanam, it is done separately; rest all are done together.