Surender,
If you want to install OTM on a single machine, you'll need more memory (8GB) and you'll need to use a different operating system, since Windows can only access 4GB total. I'd recommend Linux, though it depends on the technical skills you have available. Here's a quick breakdown of the minimal memory requirements needed by OTM:
Note: This is for test purposes only -- Production instances will require more memory and should not be run on a single server.
- Web
- Apache (256MB)
- Tomcat Java Heap (1024MB)
- Tomcat Java Overhead (512MB)
- App
- WebLogic / OAS Java Heap (1024MB)
- WebLogic / OAS Java Overhead (512MB)
- Rpt
- RptApache (256MB)
- Oracle Forms and Reports (1024MB)
- DB
- Oracle DB SGA and PGA (1024MB)
- Operating System
- Basic Memory for OS (1024MB)
Total Memory Requirement: 6.5GB
If you'd like to install on Windows, I'd recommend getting an additional server and spitting the system up into Web/App and DB/Rpt (reports) components.
Hope this helps!
Chris