Under the Sale of Goods Act, 1930, the unpaid seller may exercise the right of stoppage in transit:

Section 52(1) of the Sale of Goods Act allows the unpaid seller to exercise the right of stoppage in transit either by taking actual possession of the goods or by giving notice of his claim to the carrier or other bailee in whose possession the goods are. Both methods are available, so the full answer is "By either taking actual possession of the goods or giving notice of the claim to the carrier or bailee"; no court order is needed. The right itself arises under sections 50–51 when the buyer becomes insolvent while the goods are in transit.