Hello Vikas,
Please reference the Ariba On-Demand Enhancements page for customers. You'll need to log in using your Ariba Connect credentials.
The feature called Supplier Profile Questionnaire Field Length Validation was released in December 2015. The feature allows validations and support for text / character limitations, unsupported characters, and applies to all text and address based fields in the SPQ. This should solve the issue you are having with ERP integration and the 35 character limit needed for ECC.
Eric Coker
SAP Ariba Solution Manager