Wikipedia
Sriramachakra (also called Sri Rama Chakra, Ramachakra, Rama Chakra, or Ramar Chakra) is a mystic diagram or a yantra given in Tamil almanacs as an instrument of astrology for predicting one's future. The geometrical diagram consists of a square divided into smaller squares by equal numbers of lines parallel to the sides of the square. Certain integers in well defined patterns are written in the various smaller squares. In some almanacs, for example, in the Panchangam published by the Sringeri Sharada Peetham or the Pnachangam published by Srirangam Temple, the diagram takes the form of a magic square of order 4 with certain special properties. This magic square belongs to a certain class of magic squares called strongly magic squares which has been so named and studied by T V Padmakumar, an amateur mathematician from Thiruvananthapuram, Kerala. In some almanacs, for example, in the Pambu Panchangam, the diagram consists of an arrangement of 36 small squares in 6 rows and 6 columns in which the digits 1, 2, ..., 9 are written in that order from left to right starting from the top-left corner, repeating the digits in the same direction once the digit 9 is reached.
There is another smaller mystic diagram, called Seetha Chakra given in Tamil almanacs. In some almanacs it is given as a magic square of order 3 whereas in some others it is an arrangement of 9 small squares in 3 rows and 3 columns in which the digits 1, 2, .. 9 are written in that order column-wise from left to right.
Theses Chakras are used by the believers to predict the future. A believer takes a small flower, prays to God seeking divine directions and drops the flower randomly on a board containing an inscription of one of the Chakras. The number on which the flower falls is believed to give a broad indication of the future of the believer. For example, if the design is Sri Rama Chakra in the form of a magic square and the number on which the flower has fallen is 11 then the person can expect "victory in his/her future endeavors".