91 days is a lot of time. Liquid money should give you the option to cash out immediately. I invest a good chunk in tbills, but it's pretty much the put-it-there-and-forget-it kind of money. It gets credited into my account in 91/182/362 days and I will just repeat the cycle. I also put a good portion in liquid funds so that I can cash it out immediately when I find a good-looking deal in any of the asset classes. Besides, I hardly see any volume(in INR) so there is a weakness on the buy-side in tbills, so anything over a few Ls, you'd need to sell it at a price that would give a higher yield to a buyer. At one instance I picked up a big quantity(182d) at a ₹4.7 discount to coupon(~12% *annualised yield) from some poor sucker during the earlier days when the liquidity was negligible. The person needed to offload a huge quantity and was not finding any buyers for several days. And in the end, they conceded and sold it off at a reasonable loss. XD
Was the same story with SGBs too, until it was popularised. I miss those days when SGBs were trading at even a 10-15% discount to the spot price. Now it's selling at premiums!