As of my last update in September 2021, there were several popular Best trading platform for options  available for investors in India. Please note that the landscape of trading platforms might have changed since then, so it's essential to verify the current status before making any decisions.

Here are some of the top trading platforms that were widely used by investors in India:

Zerodha:

Zerodha is one of the largest and most popular discount brokerage firms in India. It has gained massive popularity due to its user-friendly interface, low brokerage fees, and innovative offerings. Zerodha offers a web-based platform called "Kite," which is known for its simplicity and comprehensive charting tools. Additionally, it provides mobile apps for both Android and iOS users, enabling investors to trade on the go. Zerodha also offers zero brokerage charges for equity delivery trades, making it an attractive option for long-term investors.

Upstox:

Upstox is another prominent discount brokerage platform in India, known for its competitive brokerage charges and a user-friendly interface. Like Zerodha, Upstox also provides a web-based trading platform and mobile apps for seamless trading. The platform offers various trading segments, including equities, derivatives, commodities, and currency. Additionally, Upstox offers different trading plans, including a fixed brokerage plan and a monthly subscription plan, allowing investors to choose the one that suits their trading needs.

ICICI Direct:

ICICI Direct is a full-service brokerage platform offered by ICICI Bank, one of India's largest private sector banks. It provides a wide range of investment options, including stocks, mutual funds, bonds, and more. ICICI Direct offers a three-in-one account, combining a savings account, a demat account, and a trading account, providing seamless fund transfers and transaction settlement. While it may have higher brokerage charges compared to discount brokers, ICICI Direct provides extensive research and analysis tools for investors.

Sharekhan:

Sharekhan is another popular full-service brokerage platform known for its research and advisory services. It offers a variety of investment options, including equities, derivatives, mutual funds, IPOs, and more. Sharekhan's trading platform provides advanced charting tools and technical analysis features, making it suitable for experienced traders. However, the brokerage charges might be relatively higher than discount brokers.

5Paisa:

5Paisa is a discount brokerage platform that has gained popularity for its competitive brokerage charges. It offers a user-friendly trading platform with a range of features, including advanced charting tools and research reports. Additionally, 5Paisa provides a robo-advisory service called "Auto Investor," which assists investors in building and managing their portfolios based on their risk appetite and financial goals.

Angel Broking:

Angel Broking is a full-service brokerage platform with a strong presence in the Indian market. It offers a range of investment options and features, including research and advisory services, advanced charting tools, and personalized investment recommendations. Angel Broking's "Trade" platform is known for its ease of use and comprehensive features, suitable for both beginners and experienced traders.

HDFC Securities:

HDFC Securities is part of HDFC Bank, one of India's leading private sector banks. It provides a wide range of investment options, research reports, and trading tools. HDFC Securities offers a robust web-based trading platform and mobile app for convenient trading. The brokerage charges might be relatively higher for some segments, but it provides a strong backing of a well-established financial institution.

These are some of the top trading platforms available for investors in India, as of my last update in September 2021. The Indian brokerage market is dynamic and continually evolving, with new players entering the scene and existing ones updating their offerings. Before choosing a trading platform, it is essential to consider factors such as brokerage charges, features, ease of use, customer support, and the range of investment options that align with your trading goals and preferences. Always do thorough research and compare different platforms before making a decision.