Smita,
I don't know what device you are using, but looking the address you mentioned (0x3EE000), I think you are talking about a C2000 device. If so, the majority of C2000 devices (if not all, I couldn't check) have FLASH memory at this address, therefore this is the reason why you can't change its value.
The place where variables are allocated is in the linker CMD file; in this case you must check the SECTIONS and locate .bss (global variables) and adjust it to place them in RAM. Similar thing for the other data sections.
A suggestion is to check the example linker CMD files in the directory for the device you are using and see if there are other sections that need to be moved to RAM. Also, a good reference is the Compiler User's Guide (links are at this page).
Hope this helps,
Rafael