So good resorce but not listed it is flashed locked or unlocked bootloader
Xperia C4 Dual_E5363_27.2.B.0.169_India_Generic 5.1
Sony Xperia C4 Dual (E5363) Android 5.1 firmware - Generic India
Sony Xperia C4 Dual (E5363) Android 5.1 firmware - Generic India