This stage is Deep Jungle Drift (6-4). This complete walkthrough will provide you with a 100% video playthrough and a screenshot of where you can find all the green stars. For this stage, always climb up the fences as many of the stamps and green stars are found at the upper levels. Make sure you keep your Cat Mario suit as you will need it to obtain the last green star for the stage.
Game Play Walkthrough Video
Green Star 1
After getting the stamp, jump down and grab the first green star from the clear pipes to the right. Make sure to time you exit so that you will exit on the raft.
Green Star 2
Near the check point you will find a hallow green star, trigger it to collect 8 coins. Be careful not to fall to the bottom levels. You will get the green star once you collect all 8 green coins.
Green Star 3
After the speedy drop you will get to the orange mystery box. Do not go in yet and instead use Cat Mario to climb the back wall, you will then find the last green star on top of the wall.
Climb up the blue fence to grab the stamp.