Hi Kiran,
In your GTS system, please maintain the entries in /SAPSLL/ALRG03 (as mentioned by Dhilipan); then run /SAPSLL/PREF_AGREEMNTS_SYNC_R3 program in your ECC system.
This program should replicate required entries into /SAPSLL/ALRGDAR3
Hope this helps.
regards,
Xiang Li