Hello Sonali V Baviskar

Miller indices are the indices for the lattice planes. If you have XRD data of TiO2, you must know that TiO2 has 3 common structures: Anatase, Brookite and Rutile. These structures are different, so the lattice planes will generate peaks in different positions, resulting in Miller indices in different positions. Which structure did you synthesize?

To get the Miller indies, I recommend VESTA. You can upload a CIF file, and generate them. Do you want to plot them on a Origin graph?

Thank you Ricardo. It was Anatase and peaks resemble with JCPDS card no 894921

I don't have access to JCPDS database, once it’s paid. What I do instead, and what you can do easily, is to download the software VESTA. It can open a CIF file, and generate the list of Miller indices. First, you should look for a CIF file in database like Crystallography Open Database, or AMCSD. Open it in VESTA, and you can calculate the XRD pattern and generate a Miller indices list. I am attaching the files.