Download and install the Play app, PS2 emulator for android.
Download any PlayStation 2 ISO.
Copy the PS2 ISO file to this directory on your android smartphone "Internal storage>Play data files".
Open the emulator app and tap the menu icon on top left corner and tap "Unsorted" to list all games. See this image below.
Tap any game to start playing.
Since this emulator is in developing phase so there are no specific settings to make.
The emulation will be very slow on low end phones. We recommend to play only if you have a high end phone like Galaxy S7, Galaxy Note 7, Nexus 6P or Nvidia Shield tablet.