1. I have to make 6 and half digital multimeter with high accuracy & resolution with voltage range 1V to 1.1Vdc
Reading should be updated every 1 sec.

2. I have selected ADS1246 , will it be able to measure to that resolution i.e for measuring 6 and half

3. If not, anyone else suggest other circuit

 

The ADS1246 appears to be adequate to provide the resolution you need.
Will this be interfaced to a microprocessor?
Are you then converting the digital output to a digital display?

 

Yes there is digital display.
Will interface ADS124 with ST MCU & lcd

 

I have to make it on my own board. So cannot purchase directly 6 and half multimter.

How it is done in multimeters like of FLUKE. Obviously companies won't open their schematic.
But just how it is done with so much accuracy.


meanwhile I am going ahead with ADS1246, 5 sps , external reference, separte digital and analog supplies , update reading every 2 sec, take average of 10samples & will see the results