If need to be unlocked tha bootloader. How can i unlock the bootloader ? For lava pixel v1 android 6.0
Lava has a Mediatek chipset (MT6582), you don't have to unlock the bootloader because MTK devices don't have it.
You'll need SP Flashtool and a ROM (with scatter file) and you're done.
You may want to see this thread on XDA Developers forum on flashing a Lava Pixel phone.