Introduction:
The train stopped beyond the tunnel at a small town called Sarhad. This small town is located on the route between Amer and Delhi. Let's explore the details further.

Explanation:
1. Amer:
Amer is mentioned as one of the options in the question, but it is not the correct answer. Amer is a small town located in the Jaipur district of Rajasthan, India. It is known for its historical significance and beautiful architecture, particularly the Amer Fort. However, the train did not stop at Amer.

2. Sarhad:
The correct answer is Sarhad, a small town located beyond the tunnel. Sarhad is a fictional town mentioned in the question, and there may not be an actual place called Sarhad. It is important to note that Sarhad is not a well-known or widely recognized town in India.

3. Delhi:
Delhi is mentioned as one of the options in the question, but it is not the correct answer either. Delhi is the capital city of India and a major transportation hub. While the train may have passed through Delhi on its route, it did not stop there beyond the tunnel.

4. Mountains:
Mountains are mentioned as one of the options in the question, but it is not the correct answer either. Mountains are a geographical feature and not a specific location like a town or city. It is possible that the train passed through or near mountains, but it did not stop there beyond the tunnel.

Conclusion:
In conclusion, the train stopped beyond the tunnel at a small town called Sarhad. However, it is important to note that Sarhad is a fictional town mentioned in the question and may not correspond to an actual place.