Why to rotate tyres?
Each tyre on your car supports a different weight. Moreover, incorrect tyre pressure and improper wheel alignment over a long period cause the tyres to wear out at different rate.
Tyre rotation is the practice of moving the wheels along with the tyres of a vehicle from one position to another, to ensure uniform tyre wear and tear. Regular and proper tyre rotation or inter-change ensure the tyres to wear out evenly on a vehicle, thereby increasing the life of tyres and reducing the scope of tyre borne accidents.
Wheel alignment and balancing by specialists are essential to increase the life of tyres. Ensure wheels are aligned and balanced immediately upon purchase of new set of tyre and also prior to long drives.

How often do you need to rotate?
Tyres should generally be rotated every 5000-7000 km (follow diagram)
There are other factors that may indicate you to rotate your tyres more frequently:
High speeds, heavy loads, long distances: Regular drives at high speed and long distances, or carrying heavy loads means more strenuous rotations.
Uneven wear: If you notice uneven wear on any tyre, rotate them as soon as possible.
Humming sound: If the tyres emit a humming sound or unusual vibration even on a smooth road, it might be time for rotation.

How to rotate the tyres properly?
Before you rotate the wheels or tyres, ensure whether your vehicle is a ‘front-wheel’ or ‘rear-wheel’ drive vehicle. This is usually written in the car’s manual. Generally, hatchbacks and sedans are front-wheel drive where as SUVs and MUVs are rear-wheel drives.