Step 1: Recall that IGMSY is a maternity benefit programme, so the eligible age band must correspond to the childbearing years.
Step 2: The scheme sets the minimum age at 19 years, covering pregnant and breastfeeding mothers for up to two children, which directly points to the option $>19$ years.
Step 3: The cash incentive offsets income lost while caring for a newborn and encourages institutional delivery and proper infant feeding.
Step 4: Cut-offs of 30, 50 or 65 years fall outside the typical reproductive window and would exclude most beneficiaries, ruling them out.
\[\boxed{\text{Women } > 19 \text{ years old}}\]