I agree with the above post. Having everything the same is not generally a good idea in a diverse country like India. Equality is not the same as fairness. I do think everyone should have equal access to a quality education, but definitely not the exact same education.
I think you might need to clarify your statement a bit. From my understanding, the three types of boards are already different. State boards are different from matriculation boards and both are different than central boards. If this is the case, it's going to be difficult to argue for a position that already exists. If we are speaking broadly, about the nature of Indian education, perhaps we can make a strong argument in support of your position. Naturally, with any debate proposition, research and evidence is going to be critical in proving your point. I think it's best if you proceed with this. I will say that a good starting point is to introduce the idea of differentiated instruction in your points no how the education system should be different for all boards. Essentially, differentiated instruction involves tailor making the learning and curriculum to the strengths and understanding of the student. Differentiated instruction argues that a "one size fits all mentality" to learning is incorrect and does not maximize the student's comprehension and understanding potential. I think that you can use this argument, the need for Indian education to be differentiated in regards to all boards, to make sure that all levels and learning style of students in each of the specific boards are being taught to and not taught at. In the end, the need to differentiate instruction will require Indian education to break away from the sole idea that a homogenized and uniform approach to teaching and learning reduces itself to memorization and performance on high stakes standardized assessment. Check out a thinker named Rick Wormeli who has done much research on differentiation as well as another thinker by the name of Carol Ann Tomlinson. Both give outlines and comprehensive analyses on differentiated instruction.
Different board in education system in India is necessary. India is a country with diverse culture with different religion and languages with vast diversity in economic development. It also gives freedom of choice for an individual to choose what is best for them. This increases the healthy competition and results in a better education for the society.