Hi Ashish,
What type of Order do you need to create in the ECC? Maintenance order, Sales order, Purchase order, ....?
I guess you want to create a Maintenance Order.
The transaction to create a Maintenance Order is: IW31.
Tha transaction to modify a Maintenance Order is IW32.
The transaction to display a Maintenance Order is IW33.
Let me know if this helps.
Best Regards,
Emanuel