There are statements in data sheet like "Up to 1.1 Msps conversion speed in 10-bit mode" and "Up to 500 ksps conversion speed in 12-bit mode". Does this Msps is same as 1/1.1 *10^6 or 0.909 uS? So i have the adc data at every 0.909 uS? Where the ADC clock is used in these calculations? Please advise.

 

The conversion speed is the maximum rate that you are allowed to request a data sample.
You can sample data at any speed lower than the maximum rate.

 

Does this Msps is same as 1/1.1 *10^6 or 0.909 uS? So i have the adc data at every 0.909 uS?

Yes, provided your code is able to process the data that fast.

Where the ADC clock is used in these calculations? Please advise.

Read the data sheet. All is explained in the data sheet.