If your phone doesn't have OIS or EIS on stock camera but it supported EIS. You can try a camera app which show on the video link, it work well on my phone.
Mi5s Plus doesn't have OIS but it can use DIS (Digital Image Stabilization) on non stock camera @ video 1080P, it's not bad for videos stabilization. The comparing video between stock camera(FHD) vs 1080P with DIS in this link
I have Mi5S Plus with the official international (global)ROM, had no problems to unlock the bootloader and replace with the global dev rom 6.12.8., it work fine.