Hello everyone,
Could you please tell me-
Q1-Which services are used in synchronize in broker?
Q2-There is a new file come or notify in your package folder.How to use webservices to get notify this and its initiated with trigger?How?

Are these interview questions?

Q1,2,3 - Explore Google

Q4 - WmPublic/pub.publish:syncToBroker. Refer BIS for more details.

Q5 - The question is not clear to me, you may again ask the question and post it here.

If i understand correctly your second question then file polling port is a choice for you. configure port to monitor your package folder. once you receive file in polling service then you can do whatever you want to. call a webservice or publish to messaging for trigger.