With all due respect, India is not a homogeneous country, and the one party system is not suitable for you.
If you want to play the one party system, you will fall into chaos because of the different demands of different nationalities and groups. In the end, the one party system will destroy your country.
Your current system is the one that best suits you.
When making a choice, you should consider the actual situation instead of just seeing successful precedents.
For example, India's caste system. We all know that it is a serious disease in India. In China, a CCP can easily abolish it by an executive order. But the Indian government cannot do so. Why?
Because the caste system is an important part of Hindu culture. India has more than 2000 ethnic groups and hundreds of languages. They think they are Indians because they have the same Hindu culture.
If you have damaged the foundation of Hindu culture, why should those different ethnic groups with different languages and colors stay in the same country as you?
Therefore, the actual situation does not allow this. This is true of the caste system and the one party system. If you forcibly implement the one party system in India, you will eventually be divided because of the one party system.