Iphone 6 SIM Lock NTT Docomo Any ideas?

Hello everyone, I’m complete new in these apple world and weird SIM Locks and unlocks…

Which patch I have?

-Carrier unlock, the owner was on Docomo, and they said they can’t do it, even pay..

-As I was reading, right now with Jailbreak I can’t unlock it… and phone are under iOS 9.2, even not Jailbreak yet…

-IMEI SIM unlock, its works on Docomo? Could I update the iOS version of phone? use apple store? connect to Itunes?

-X-Sim, It works on Iphone 6 and iOS 9.2? I see they are several kinds… which one its the best?

I’m really lost, I would appreciate any help…

thanks