Dear Ramakrishna,
For customs declaration in GTS,you need to fallow below main settings which are mandatory.
Point 1--ECC---Switched on for SD0C
Point 2--GTS----Maintain legal regulation ,activate L.R,
Point 3---Mapping required for GTS SO--GTS SO,Item category mapping.
Pont 4---Maintain Numbering schema and assign this numbering schema to LR.
Point 5--Define technical medium for message of general documents ( Print/electronic )
Point 6--Define message scheme and communication with customs.
Point 7--Control setting for communication process.
point 8--Define determination of activity sequence.
Please let me know further help on this.
Thanks
Venu gopal