What is the meaning of at what time you will be there?

Answer 1

The question, "At what time you will be there?" is incorrect in speaking or writing. You can correctly ask:

1. What time will you be there? or
2. When will you be there?

The first question, What time, means you are asking for a specific clock time. For examples:

I will be at the store to pick you up at 5:15 p.m.

I plan to get to school no later than 7:15 a.m.

I want to be at the party by 9:00 p.m.

When will...is less specific. It does not require a clock time, though it can be answered with a specific time. For examples:

I will pick you up this afternoon.

I will pick you up about 2:15 this afternoon.

I will go to the store this evening.

I will go to the store around 7 p.m.

Or the answer to When will... can be combined:

I will go to the store this evening, around 7 p.m.

Answer 2

It is enquiring about the time - usually in terms of the local time - when you will be at a location which has been determined in an earlier part of the conversation.

Answer 3

This phrase is asking for the specific time when you will arrive at a certain location. It is seeking a clear answer regarding the expected arrival time.