About GTA 5 LITE :
“GTA 5 Lite” refers to a modified or compressed version of the popular video game “Grand Theft Auto V” (GTA 5) that is designed to run on devices with lower specifications, such as low-end smartphones or older computers.
The “Lite” version typically has reduced graphics and features compared to the original game, but it still allows players to enjoy the gameplay experience of GTA 5 on their devices. However, it is important to note that downloading and using modded or pirated versions of games can be illegal and may also pose security risks to your device.
Basically GTA 5 Lite is a mod which is installed in GTA 4 in order to add the whole map of GTA 5 with missions, Features & Storyline. You can access the mod from here