The first step could be to import the file into Mathematica in TSV
format and then clean it up a little:
data = Import[
".../RespuestaEscalon_A10_k_1.txt",
"TSV"];
cleanedData =
data /. str_String :> ToExpression@StringReplace[str, "," -> "."];
ListPlot[cleanedData[[All, 1 ;; 2]]]
There may be a faster way with SemanticImport
, but the default settings do not give directly usable results.