The answer of Mr Valliappan is perfect. Adding....the town buses are the cheapest way to reach. It is hassle free. I also suggest that if you have time please book a cottage and stay one full day to experience everything at isha.
Address: Isha Yoga Centre, Velliangiri Foothills, Isha Vihar Post, Coimbatore, Tamil Nadu 641114
Phone:0422 251 5345
6 AM to 8 PM everyday.
There are buses from Town Bus Stand Gandhipuram that go straight to the gates of Isha. Timings are with 1-2 hours gap. Or you can take cabs from a nearby point called Alandurai. 30 KM from Gandhipuram, Coimbatore. 10 KM from Alandurai. Total one hour by road. To return, there are taxi cabs available near car park or taxi can be called on app (Uber or Ola) or Red Taxi or Taxi Taxi)
Have a good trip and enjoy the serene atmosphere...
You can go by public transport if you are not worried about time and comfort. From Gandhipuram to Dhyanalinga temple, buses are available every 45 minutes during day time.
If you are short of time or want to travel comfortably, you can hire a call taxi. However beyond city limits (selvapuram) the rates are different.Better to engage for to and fro with waiting charges.
A taxi would be the best way to go and come back!!
Since public transport is not accessible near the location,its better to book taxi through a mobile app.
There are certain city transport buses.
However prefer to hire a cab for the day to travel to and fro.
Else you can travel by auto/metered cabs. Crowds throng there, so while returning options should be there.
For further details you should google search Isha foundation and that should suffice!
Get quick answers from Dhyanalinga Temple staff and past visitors.