Question

the train leaves the stations before I reached there(correct the sentence using past perfect sentence)​

Answer 1

The correct sentence should be, When I reached the station, the train had left. According to the rules of 'tenses' , when there are two past actions, the first past action should take past perfect tense , and the second past action should take simple past.

Answer 2

The train had left the station before I reached there.

hope this helps you.