comparison of multivariate (4 DV and 1 IV) datasets (data matrices)

I want to compare 06 different Multivariate datasets (data matrices). Each dataset consists of SAME number of columns but different number of rows. Number of columns represent the variables (4 dependent variables and 1 independent variable). All variables are quantitative in nature. Independent variable is the "number of observations" and dependant variables are probabilistic in nature. (All of these datasets are obtained after MATLAB simulations by varying the sampling time)

I've tried Multivariate and PCA analysis but the results don't give me any useful information. I want to observe the differences/similarities among these datasets. Moreover, I want to know if these datasets exhibit any trend or related to each other ?

Please suggest me any Test/Analysis. I can provide more information if needed.