Answer: 100 shares
For one share: brokerage \( = 0.2\% \text{ of } 50 = ₹\,0.10 \)
GST on brokerage \( = 18\% \text{ of } 0.10 = ₹\,0.018 \)
Amount received per share (selling, so subtract):
\[ 50 - 0.10 - 0.018 = ₹\,49.882 \]
\[ \text{No. of shares} = \frac{4988.20}{49.882} = 100 \]