If you had walked into one & showed interest in buying a house, chances are the developer would have asked if you had a pre-approved loan for mortgage. And if you had never walked into one, just wait until it happens. It is quite pushy for them to ask that, and for good reasons.
Yes, it still depends upon the developer. All developers are not the same & they come across in many ways. They meet, greet & chat with you in different manners. This is real estate & there is no one way to be. But then, this is a question which every developer should be asking you whether you are pre-approved before signing a deal for the property. However, some don’t because they feel it may be a bit pushy. They may worry about offending you. It is sensible that they should ask because it is important for them to know & equally important for you to be preapproved. Even if it comes across a bit pushy or invasive, the question is relevant & a lot
depends upon how the question is asked. As a home buyer you should be expecting the question & be prepared to answer this in a positive manner.
It is not because they want to size you up or want to know how much you can spend. The reason they want to know that you are pre-approved is that they want to make sure you are serious & qualified for buying the property. Moreover, they have valid reasons for wanting to know. 
They want to make sure that they are working with someone who will actually buy the property. This is a matter of being careful that they are not wasting their time. There is no way you can fault them for that.
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Developers also want to know how much you are pre-approved for. This will help them give you the correct advice. It will also let you know if you can afford the house. It would not be good for both of you after going through an elaborate procedure to end up realizing that you cannot afford the property.
Even if you had just started looking for a home & are not yet pre-approved, expect that this question would be asked. Do not be offended when the developer asks you this question. Developers are thorough & thoughtful about their business & it is a good sign that they are asking this question. Moreover, even if you did not need to avail a loan for buying the property, the developer would still be asking you to get a letter from the bank that you were having sufficient funds to pull through the transaction. It would be ideal that you get pre-approved even before you start looking for a house. It would also be sensible that you let the developer know that you are pre-approved even before they would ask.
Hyderabad real estate market is in top gear right now. Northstar Homes which is one of the leading real estate developers in Hyderabad has quite a few ongoing projects in the finest neighborhoods of the city. They have an enviable track record of developing ecologically sustainable projects with high safety standards alongside unique design propositions. Take a look at the Hillside at Gandipet or the Airport Boulevard near RGI Airport to experience the difference.