The drawbacks of PDS system are ;-
Most probably the government is putting more stress in producing what and rice due to which .farmers grow only wheat and rice in their fields.Due to which the amount of wheat and rice is increasing very fastly(about 63 million tones while maximum capacity of buffer stock is 24.3 million tones) . This causesa lot of problems of storage and transportation
Also the PDS is working for many years then also it is unable to remove hunger from india
Even due to advent of various programs different kinds of malpractices were still prevailing in the society .Like distribution of grains of lower quality at higher rates at fair price shops by th shop owners and selling the good quality grains at higher rates to gain profit at nearby market shops.