I have a Reliance LYF mobile phone and want to enable the developer mode. I looked for all options in the settings but haven't found anything to enable developer mode. Is the developer mode option available on it?

There are some locations where internet in my Redmi 4 phone works very fast and every time. But there are some locations (like the place currently i am living) where it shows full network but most of the times internet stops (becomes very slow , like just keeps buffering and never loads even a simple web page). During late night it runs without any hassle at same location. Now at same location , when i use some one else phone (LYF) , internet works throughout the day .It becomes sometime slow but then also is able to load 360p video on you tube. Problem is not in sim card. Any possible reasons and solution for this.