Hi Sunil,
it seems you designed a validation for this table. You need to go to Record View -> Validation tab and check the validations there one by one. There is one in it (maybe more), that doesnt allow you to create the hierarchy element, because validation(s) are failed.
Solutions:
1) Change Validation Action to "None" (validation not run) or "Warning" (validation is run but gives you only a warning)
2) Check the validation content and make sure that the created record fullfills the criteria of the validation. Then the record can be saved.
For further info have a look at the MDM Data Manager Reference Guide (SAP NetWeaver Master Data Management (MDM) 7.1 – SAP Help Portal Page)
Best regards,
Gábor