Determination of Crystal Structure from Powder Diffraction by Rietveld Method; Development of Methods and Techniques in X-Ray, Electron and Neutron Diffraction; Crystallography of Phase Transformation, Martensitic Transformation in Shape Memory Alloys; Texture Studies, Defect Structure and Microstructure Characterisation; Material Structure: Metals, Ceramic, Polymers, Amorphous Materials, Nanomaterials and Thin Films.