Could not start startWeblogic (domain) due to ' Error occurred during initialization of VM... ' error

It has always been with JVM memory allocation issues whenever you install Oracle SOA Suite for first time.Upon starting your weblogic domain you will end up with error like this

Error occurred during initialization of VM
Could not reserve enough space for object he
Could not create the Java virtual machine



This type of error is mainly due to heap size being larger than your system's physical memory

Resolution:
go to file in :     
<domain home>\user_projects\domains\<domain>\bin\setSOADomainEnv.cmd/sh

in my case it is  
D:\Oracle\Middleware\user_projects\domains\base_domain\bin\setSOADomainEnv.cmd

change the below config of -Xmx1024m to -Xmx768m
i.e from  
set DEFAULT_MEM_ARGS=-Xms512m -Xmx1024m 
to  
set DEFAULT_MEM_ARGS=-Xms512m -Xmx768m


Note: there is no rule you only need to set to 768. You can try with number that will start your weblogic server.