This question seems to be incomplete. However, there´s enough information to find the right answer.
Answer:
The potato crop had failed, leaving his family unable to buy what they needed. So Nathu left his village to look for a job. Someone sent him to the limestone depot, where he got hired by Pritam Singh to clean and look after his truck.
Step-by-step explanation:
In The Last Truck Ride, by Ruskin Bond, we learn that the potato crop in Nathu´s village had failed, leaving his family unable to buy anything they couldn´t grow despite the summer drought, which was only onions and artichokes. So Nathu left his village to look for a job in the town in the valley. Once there, someone sent him to the limestone depot, where, despite not being able to get a job at the quarries, he did get hired by Pritam Singh to clean and look after his truck.