Hi Vinay
In SAP System copy R3load used either Backup /restore or Attach / deattach method.
Which method (R3load or backup/restore) is recommended in homogenous system copy?
In your case you have to use the source system export using either SWPM or old SAPINST method.
Can we build target system with different SID by using backup/restore method?
Yes, You can change the SID in target at the time of system import, before that read the system copy guide.
BR
SS