So between treasury bills and fix deposits, which is good and profitable to go in for

• Treasury bills are generally considered "good" for investors who prioritize safety and liquidity. They have virtually no risk of default because they are backed by the government, making them ideal for preserving capital or for short-term funds you might need quickly. However, their profitability (returns) is typically lower.
• Fixed deposits can be more "profitable" in terms of higher interest rates compared to T-bills, especially for longer terms. They are "good" for investors willing to accept slightly higher risk (bank default, though often insured) and lower liquidity in exchange for potentially better returns.

If your priority is maximum safety and easy access to your money, T-bills might be better. If you're comfortable with slightly more risk for potentially higher returns and can lock up your money for a period, fixed deposits could be more profitable.