Want to buy best Smartphones between 30,000/- to 48,000/-

Hi,
I guess you can get a much better configuration if your willing to spend 30K or more. So my suggestion would be Vivo smartphone. Vivo has anwide range of smartphones with both high end and low end smartphones. With your budget Vivo can provide you the best phone which will take great care of your priorities.

Go for HTC Desire Eye. It has 13 MP front and rear camera with flash. Top of the line hardware and is dust and water resistant

If you want a phone between 30K-50k you can go for Samsung Note 3. There are only 5-6 difference between Samsung note 3 and Samsung note 4. Note 3 is better than iphone 6 plus. In everything.

Go for Samsung Galaxy Note 3.It offers Powerful configuration and Excellent Display.It comes with 5.7 inches (Large) display,13 MP Primary camera and 3200 mAh, Li-ion bettery.Samsung Galaxy Note 3 is definitely a worth buying device.Go for it.Get complete details here - http://www.91mobiles.com/samsung-galaxy-note-3-price-in-india

Samsung galaxy note 4... you will get on ebay for 40K brand new here is the link below.. This is the best phone currently period.. Its has all the latest features and then some more.. Awesome spec too
i have purchased 2 phones from him and they are all good..

http://www.ebay.in/itm/Deal-18-New-Imported-Samsung-Galaxy-Note-4-32GB-/131433063934?pt=LH_DefaultDomain_203&hash=item1e9a0565fe

suggest me top 5 Dual sim smartphones price below 9,000/-which has:
1. at least 1gb ram
2. good battery backup

Have a look on Vivo Xshot.
It got great camera both back (13mp, ois, f1.8) and front (8mp), dedicated DAC for better audio, goof battery life.
However you might not get very often Android update, but I don't see it as a spoiler.
Other than this, I think Nexus 6 is also great phone.

Go for Nexus 6 .It is good.

need review on Sony Xperia Z3. Is it good choice to buy it?

That depends upon what kind of Material or skin you chose..
1.In terms of material HTC is best...
If you prefer camera I would recommend you HTC One M8 Eye..with 13 mpx rear and 5 mpx front camera. It is a full metal phone and promised Android update for 2 years.Battery is 2600 mAh but it runs more than a day easily.
2. Nexus 6 comes well within your range if you have large hands for a 5.96 inch fat boy.
well it is a pure Google phone and you get updates first and feel like a VIP. It has even got a very good camera with 13 mpx OIS camera and a QHD Display.Battery is more than 3000mAh, so lay back and enjoy it easily for a day.
3. iPhones will got out of the range you mentioned as it will cost Min of 52,000 for the newest Models.
4. Samsung Note is a very good Choice as it has got the best screen with 5.7 inch QHD display and best Android camera at 16 mpx. But it costs 58000 and the software is the worst part.

I bought an LG G3 around four months ago, and am pretty happy with it so far. It's in the budget you specify and meets all the requirements except for battery backup - it's only average. I don't use it very heavily, but I keep two bluetooth devices connected at all times, and Wi-Fi and 3G on - I usually have to charge it for half an hour every morning, and one and a half hour every evening on getting home. If you're going out somewhere at night, you definitely want to charge it up before leaving office. The good thing is that it fast charges so in an hour and a half it's usually back to 100%.