At what age are children typically most ready to enter kindergarten?

In India, kindergarten is divided into two stages- lower kindergarten (LKG) and upper kindergarten (UKG). Typically, an LKG class would comprise of children 3 to 4 years of age, and the UKG class would comprise of children 4 to 5 years of age. After finishing upper kindergarten, a child enters Class 1 (or, Standard 1) of primary school. Often kindergarten is an integral part of regular schools. In most cases the kindergarten is run as a private school. Younger Children are also put into a special Toddler/Nursery group at the age of 2–2½. It is run as part of the kindergarten.