P. C. Mahalanobis is widely regarded as the father of Indian statistics for his pioneering work in the field, including the development of the Mahalanobis distance and the Mahalanobis matrix.

C. R. Rao developed the principal component analysis (PCA) method, which is a statistical technique used to reduce the dimensionality of data by identifying the principal components, which are the directions of maximum variance in the data.

S. N. Roy made significant contributions to sequential analysis and non-parametric statistics, including the development of the Roy's sequential probability ratio test and the Roy's largest root test.

H. C. Das Gupta is renowned for his contributions to design of experiments and quality control, including the development of the Das Gupta's method for constructing orthogonal arrays and the Das Gupta's control chart.

P. C. Mahalanobis developed the Mahalanobis distance, which is a measure of the distance between two multivariate data points, taking into account the correlations between the variables.

C. R. Rao made significant contributions to statistical inference and decision theory, including the development of the Rao-Blackwell theorem and the Rao-Cramer inequality.

S. N. Roy developed the Roy's largest root test, which is a statistical test used to test the equality of two covariance matrices.

C. R. Rao made significant contributions to multivariate analysis and discriminant analysis, including the development of the Rao's F-test and the Rao's V-test.

H. C. Das Gupta developed the Das Gupta's method for constructing orthogonal arrays, which are used in design of experiments.

S. N. Roy made significant contributions to sequential analysis and non-parametric statistics, including the development of the Roy's sequential probability ratio test and the Roy's largest root test.

P. C. Mahalanobis developed the Mahalanobis distance, which is a measure of the distance between two multivariate data points, taking into account the correlations between the variables.

C. R. Rao made significant contributions to statistical inference and decision theory, including the development of the Rao-Blackwell theorem and the Rao-Cramer inequality.

S. N. Roy developed the Roy's largest root test, which is a statistical test used to test the equality of two covariance matrices.

C. R. Rao made significant contributions to multivariate analysis and discriminant analysis, including the development of the Rao's F-test and the Rao's V-test.

H. C. Das Gupta developed the Das Gupta's method for constructing orthogonal arrays, which are used in design of experiments.