Wikipedia: The national flag of Bangladesh (Bengali: বাংলাদেশের জাতীয় পতাকা) was adopted officially on 17 January 1972. The red disc is for the sun rising over Bengal. It also is for the blood of those who died for the independence of Bangladesh. The green field stands for the lushness of the land of Bangladesh.
Interestingly, the red disc is offset slightly toward the hoist so that it appears centred when the flag is flying.
Wikipedia: The flag of Peru was adopted by the government of Peru in 1824, and modified in 1950. It is a vertical triband with red outer bands and a single white middle band. Flag day in Peru is celebrated on 7 June, the anniversary of the Battle of Arica.
The flag comprises of three equal vertical stripes of red, white, and red. Red represents bloodshed while the white represents peace and justice. The Peruvian Coat of Arms appears centred.
Wikipedia: Indonesia’s flag's colours are derived from the banner of the 13th century Majapahit Empire. However, it has been suggested that the red and white symbolism can trace its origin to the older common Austronesian mythology of the duality of Mother Earth (red) and Father Sky (white).
Wikipedia: The National Flag of India is a horizontal rectangular tricolour of India saffron, white and India green; with the Ashoka Chakra, a 24-spoke wheel, in navy blue at its centre.
Gandhi first proposed a flag to the Indian National Congress in 1921. The flag was designed by Pingali Venkayya. In the centre was a traditional spinning wheel, symbolising Gandhi's goal of making Indians self-reliant by fabricating their own clothing. The design was then modified to include a white stripe in the centre for other religious communities, and provide a background for the spinning wheel. Subsequently, to avoid sectarian associations with the colour scheme, saffron, white and green were chosen for the three bands, representing courage and sacrifice, peace and truth, and faith and chivalry respectively