Hi Karthik,
Please note that Office 64 bit version are NOT supported for BEx tools.
Can you please refer the following SAP KBA Note for more details about this:
1846536 - BEx Analyzer 3.x & 7.x : Support for MS Excel 2013 and Microsoft Windows 8
Also, please refer the following SAP KBA Note:
147519 - Maintenance strategy / deadlines for SAP GUI
Thanks & Regards,
Sapna