Hello trangntq and welcome to the DigiKey TechForum.
We have this forum post that goes over Infineon suffixes.
The A would call out that it is Halogen Free and RoHS compliant.
The TM would call out that it is tape and reel.
The A1 would be an Infineon Designator.
That would indicate that IAUC24N10S5L300ATMA1 is the same as IAUC24N10S5L300, with the added information above making it an orderable part number.