The clutch holding requirement for starting a motorcycle can vary depending on the specific model and manufacturer. However, in the case of the Royal Enfield TB350X (ABS), it is not mandatory to hold the clutch while using the electric start, even if the gear is in neutral.
Royal Enfield motorcycles, including the TB350X (ABS), typically have a safety mechanism that prevents the engine from starting unless the bike is in neutral. This means that as long as the gear is in the neutral position, you should be able to start the motorcycle using the electric starter without needing to hold the clutch lever.
The owner's manual will provide you with the most accurate and up-to-date information regarding the starting process and any specific requirements or recommendations.