TMF is about 1.5 hours drive from Mumbai though if one leaves early you can get there in an hour.
Take the Mumbai-Pune Expressway and take the first exit at Shedung and get onto the old Mumbai – Pune highway. Drive for around 20 minutes till one hits a T-Junction, which is called Chowk Phata. The left turn there goes towards Karjat and if one were to go straight one would reach Lonvala. Take the Left turn towards Karjat and about 200 ft on your left, next to ND Studio, you will find Tooth Mountain Farms-Neelam Farm Stay.
Take the Pune-Mumbai Expressway, and take the exit at Khallapur. Get onto the Old Pune-Mumbai highway, and drive for about 30 minutes towards Mumbai till one hits the chowk phata, which is a T-Junction with one road going towards Karjat. Take a right there and about 200 ft on your left is Tooth Mountain Farms-Neelam Farm Stay, right next to the famous ND Studios.