If amavasya(New moon day) falls on two days ,(i.e., from today afternoon to tomorrow after), can I perform tharpanam on the second day morning? Please clarify. This situation comes to everyone's life when first day was missed due to unavoidable reasons?
I am afraid that once you have missed the day then you may not perform it later. You would have to wait for the next amavasyA for the pitru tarpanam.
It is advisable to be prepared well in advance with respect to dates and items needed for the tarpanam.
Apart from this, the mahAlaya paksha is the main time for performing the shraddha to the pitrs.
You can do some prayashchita for missing the monthly amavasyA tarpanam.
Especially, the sarva-pitra amavaya is the main day which should not be missed.
Further, you can also perform the pitru tarpanam during samkranti/sankramana.