Hi all,
The above problem has been solved.
After upgrading / deploying SAP HANA SP 06 on AWS "PLEASE UPDATE YOUR HANA STUDIO and HANA CLIENT to REVISION 60" to avoid any unnecessary and unwanted technical problem 
As mentioned here HANA Developer Edition SPS6 Status & Roadmap"With the just released SPS6, the allocation after startup of the DB is back to ~13GB" - Now refer to the screen shot for more detail.
Thanks for the support Juergen
Regards
Kumar