There were several factors that attracted European trading companies to India:

1. Rich and diverse resources: India was known for its abundance of valuable resources such as spices, textiles, precious stones, and metals. These resources were highly sought after in Europe and could fetch high profits.

2. Strategic location: India's geographical location made it an ideal trading hub. It was situated on the trade routes between Europe, the Middle East, and Asia, allowing for easy access to various markets.

3. Established trade networks: India had a well-developed and ancient system of trade networks, both within the country and with neighboring regions. European trading companies saw great potential in tapping into these existing networks to expand their own trade operations.

4. Political instability and weakened empires: During the 16th to 18th centuries, India experienced political instability and the decline of powerful empires such as the Mughals. This created opportunities for European trading companies to establish themselves and gain influence in the region.

5. Technological and naval superiority: European trading companies, particularly the Dutch, Portuguese, French, and British, possessed advanced naval technology and military power. This allowed them to dominate the seas and establish maritime control, which was crucial for conducting trade with India.

6. Competition among European powers: European countries were in fierce competition with each other to establish colonies and dominate global trade. India, with its rich resources and strategic location, became a significant battleground for these rivalries.

Overall, the lure of wealth, access to resources, strategic advantages, and the opportunity to expand their influence in a politically unstable region were the main factors that attracted European trading companies to India.