Hello! That sounds like an exciting trip covering some beautiful places in South India. Here are some travel tips for your journey.

Best Time to Visit:
Chennai, Coimbatore, and Madurai can be visited throughout the year but the best time would be October to March when the climate is more pleasant. For Ooty, the ideal time is during the cool months of April to June and September to November.

Route and Accessibility:
All these cities are well connected by road, rail, and air. You can start from Chennai, then move to Coimbatore, followed by Ooty and finally Madurai. Buses and taxis are available to commute between these cities. All the cities have railway stations and Chennai, Coimbatore, and Madurai also have airports.

Accommodation and Booking:
All these cities have a wide range of accommodations to suit different budgets. It's advisable to book your accommodations in advance, especially in Ooty which is a popular tourist destination. Booking platforms such as Booking.com, Airbnb and MakeMyTrip can be used.

Clothing and Essentials:
Carry light cotton clothes for Chennai, Coimbatore, and Madurai. For Ooty, pack some light woolens or layers as it can get quite chilly, especially in the evenings. An umbrella or raincoat could also be useful as these regions experience sudden showers. Sunscreen, bug repellents, and personal medication are also essentials.

Health and Safety:
Follow basic safety precautions and avoid isolated areas at night. Stick to bottled water to avoid any stomach upsets. If you have any health issues, check with your doctor before making the trip, especially since it includes a visit to the high altitude area of Ooty.

Local Etiquette and Respect:
South India is known for its rich culture and tradition. Respect local customs and religious beliefs. Temples are important places of worship, so dress modestly while visiting them.