Hi Prashanth and Satya,
I just saw your replies and just to add on to futher to my explanations above.
I found a a document (Link below) which listed all the notes that pertained to inconsistencies in RSMDATASTATE table.
http://wiki.scn.sap.com/wiki/display/BI/All+about+RSMDATASTATE+table
Which led me to the note 1633303 this note is also mentioned in the Note 1838739 which prashanth mentioned.
http://service.sap.com/sap/support/notes/1633303
As mentioned in the note I could see some inconsistencies in the table RSDCUBE in the field BIA_STATUS which was Blank even though there was BWA Index for the cube in question. So had to maintain the value in table and then I was able to navigate to the Rollup tab.
@Prashanth Konduru,
I had checked the Note 1838739 but the resolution mentioned was already in place in the table RSMDATASTATE. But progressed to the 2nd resolution (i.e., note 1633303) as mentioned above.
Thanks & Regards,
Sunil