Thank you @teddy0209 and @lesscro for the help. I followed both your suggestions and went ahead with the installation but it was in vain. I was still stuck while booting up.
I had made a similar comment in another thread, where @KoryandR replied to me and sent me to this comment. There I came to know about a modded module created by @-us3r- based on @SolarWarez's module. The title of the file is "xposed-v87.1-sdk23-arm64--MIUI9-edition-by-SolarWarez-20170612-mod_by_us3r.zip". I flashed the zip through TWRP 18.104.22.168. My mobile successfully boot up and module is working flawlessly. Thank you everyone of you. Much appreciated.
Links to the file: