I have reading on internet, difference between two. Some keys ponts for delta are: High Stability & low power & added latency.
While for SAR ita: lower stablity than delta, higher power & low latency.

But if I have both delta & sar adc of 16 bits. What will be the difference in stability or accuracy.

 

This article has a good comparison of the two. See pg 8, for example.
http://www.ti.com/europe/downloads/Choose the right data converter for your application.pdf
A good engineer would also tell you that accuracy and stability are also very much dependent on things outside of the ADC itself. The power supply has to be very stable and noise free. The input signal should be noise free, or as close as possible. Pcb construction needs to follow best practices for spurious noise pickup reduction. Mixing analog and digital circuits in the same system (or on the same board) takes careful layout to prevent, among other things, digital signal switching spikes from being picked up in the analog components. Sometimes that requires extra thought about signal shielding. Often, these types of circuits have separate analog and digital ground planes, that are only joined, if at all, at a single point. Just some other things to think about.