Hi Pankaj,
if I understand your question correctly, the quick way might be to utilize the methods provided by timeseries class. One possibility to reduce the number of data "columns" is shown below along with cropping the timeseries to a given start and end time:
 % Create timeseries
 time = 0:0.01:2;
 for ik = 1:4
   data(:,ik) = sin((2 * pi * 5 * time) + ((ik-1) * pi/2));
 end
 TS_initial = timeseries(data,time);
 % Extract part of the timeseries
 startTime     = 0.5;
 endTime       = 1.5;
 colsToExtract = [2 3 4];
 if size(colsToExtract,1) > 0
    % copy the original time series
    TS_extract = TS_initial;
    % select the data
    TS_extract.Data = TS_extract.Data(:,colsToExtract);
    % extract for a given time range
    TS_extract = TS_extract.getsampleusingtime(startTime,endTime);
 end
Kind regards,
Robert


