The plages are large magnetic structures that appear in the chromosphere part of the sun. Like sunspots, plages appear at higher latitudes during the beginning of the cycle, and as the cycle progresses, they occur at lower and lower latitudes. The plages are long-lived compared to sunspots. The plages appear in the solar images taken in Ca-K 393.4 nm wavelength. These plages can be a good proxy for the measurement of the rotation speed of the chromosphere. There are various ways to measure the rotation speed. In this talk, I will talk about my project work on computing the rotation rate of the chromosphere using Kodaikanal heritage Ca-K data.BGS Office