Please suggest me chip or a circuit, which can act as an universal Analog Input. I'm looking for a chip/circuit where I can apply any of the following inputs.
Thermocouple Inputs
RTD Inputs
Resistance Inputs
Current
Voltage
I think no chip like as your application. You would make your circuit own. You required number of multiplexer/demultiplexer chips. Download 4051B datasheet and put your mind with this. You will be found your circuit from datasheet.
I doubt you will find anything as universal as you imagine,
but there is a lot of recent activity in "AFE" (Analog Front
End) ICs, generally meant to amplify, clean and protect
analog signals destined for an ADC's input. Check TI, for
starters, and then just about anyone else selling A/D
products.