Post [Q] Check xperia z country of origin/Using si number

Hey
Before postingthis thread,i google forum xda to check si number i.e customization number of xperia z to download stock rom, But i did not find .
My xperia z C6603 Si is 1270-1406.
Can any body help. that how may i check xperia z SI With region specifications.
Thank you