Hello Aman,
Good day.
Just an additional comment to Riyaz's answer, name changes are not permitted in Amadeus once a PNR has been ticketed. If you try to add an infant in the normal way to a ticketed PNR, you will receive an error.
For example, if you try to add an infant to passenger 1 using this entry:
1/(INF/JOE/25MAY16)
System response: RESTRICTED - FA/ET EXISTS
Before using the above entry, you must contact the airline and confirm that they're OK with you adding the infant in this way. Some carriers may prefer to make this amendment for you and issue the infant ticket themselves. For more information, kindly check this article in Service Hub How to add an Infant name to an already ticketed PNR.
Hope this helps.
Best regards,
Grace
