Sony.yt - International Sony Forum

Docomo Xperia Z3 SO-01G  marshmallow ftf needed anyone help?

Use Xperia firmware downloader to get firmware for that phone model straight from Sony. or search japanese gsm forums, that you can do for free. Or you can use paid services like our Sony Ericsson Online Service, if requested firmware is available

can we install international version marshmallow d6603 to docomo Z3 SO-01G?

I would not recommend that. Why? There are only japanese apps in DoCoMo firmware, you can root your phone and delete them. But if you want to risk damaging your phone, i can flash generic d6603 firmware on your own responsibility