For your Suzuki Gixxer 155, considering your requirements of occasional long rides and daily commuting in Mumbai, I would recommend the Michelin Pilot Street Radial or the Pirelli Angel CT tire.
The Michelin Pilot Street Radial is designed for sporty performance and provides excellent grip on both wet and dry surfaces. It offers precise handling, stability, and good longevity, making it suitable for both spirited riding and regular commuting. The radial construction of the tire enhances comfort and provides a smooth ride, which can be beneficial for longer rides.
The Pirelli Angel CT is a sport-touring tire that offers a combination of performance and durability. It provides excellent grip and stability in various weather conditions, including wet surfaces. The Angel CT also offers good mileage, making it a reliable option for long rides and daily commuting.
Both of these tires have been well-received by riders and are known for their reliability and performance. They strike a balance between grip and longevity, which aligns with your requirements.
Remember to regularly check tire pressure, maintain proper tread depth, and follow the manufacturer's recommendations for tire maintenance to ensure optimal performance and safety.