The Short Answer
No mobile game file is offered on this site, and there is no file page here. This page explains why, so the decision is transparent rather than hidden behind a missing link.
The Project Is Unofficial
The Dota 2 Mobile fan project is an unofficial fan-made adaptation, not an official Valve release and not the full PC game. Handing out an unofficial adaptation would blur the distinction this site exists to protect, and it would risk misleading readers into thinking a fan project carries Valve's backing. It does not.
Safety Comes First
Unofficial mobile files from unknown sources are a common route for harmful software to reach phones, and they can put accounts at risk when they ask for login details. We will not point readers toward that risk, and we will not dress up an unofficial file as a safe option.
Respect for the Rights Holder
Valve owns Dota 2. Content on this site will be removed promptly on request from the rights holder, and offering no file at all is the simplest way to respect that position. If you are the rights holder and you want content removed, the contact page explains how to ask.
What This Site Does Instead
Instead of files, this site offers clear information: what the fan project is, how it differs from the official PC game, how real Dota 2 works, and how to start with the real game on PC. Reading about the fan project is free and safe, and it leaves you better informed than a file from a stranger ever would.