Is it possible to calculate RRT (relative retention times) in Clarity?

Yes, you can add the User Column which displays RRT according to a Compound Name. To do this, follow these instructions:

•  In the chromatogram, you need a defined peak name from the Calibration Table which will be used for the calculation of other peaks' RRT. Alternatively, you can name the peak directly in the chromatogram by using the Force Peak Name function.
• Add a new User Column in the Result Table and in the Expression field type [Reten. Time]/[COMPOUNDNAME$Reten. Time]. COMPOUNDNAME is the compound that will be used as a reference peak to calculate the retention times. You can generate the calculation by choosing the Reten. Time in the Columns field, then the "/" sign and for last click the Special Values button and click on the Compound item. Type the name of the column in the Title field and hit OK. A new column appears in the Result Table containing the calculated RRT.