what dashlaunch are you using ? 3.09 works, dashboard version of console ? GTA needs 16202 minimum, have you blocked create live account and connecting to live in family settings ? i find sometimes this helps.
looks like you installed correctly i did it with this info.
1. The contents of each dvd are this:
DVD1 = Mandatory content Installation. You need this dvd to play the game
DVD2 = Single player + GTA Online
Which means the first dvd is just a normal DLC/additional installation and not an actual game.
2. Setup each DVD like this.
DVD1:
This DVD has to be installed on your console\'s internal HDD or a USB drive which was formatted using your console. The size of the USB drive should be enough for the entire disc. Extract DVD 1 using Xbox Backup Creator (or any other application you prefer) and copy the \'content\' folder from the extracted files to your internal HDD or the external xboxformatted USB drive.
When you transfer your files, they should look like this
HDD:\\content\\0000000000000000\\545408A7\\0000000 2\\545408A700000000
HDD:\\content\\0000000000000000\\545408A7\\0000000 2\\545408A700000001
HDD:\\content\\0000000000000000\\545408A7\\0000000 2\\545408A700000002
HDD:\\content\\0000000000000000\\545408A7\\0000000 2\\545408A700000003
i.e. 1 folder called 00000002 and 4 files inside it.
DVD2:
Files from DVD 2 have to be treated like a normal game which means you can either make an ISOrip (using XBC or other apps) and use that on your JTAG/RGH or make the ISO into a GOD container.
NOTE: Do not make a GOD container of the first DVD, your game will not work if you do that.
hope this helps