Hello Ashok kumar.
For import excel files into GST offline utility, you get an error if columns are not exactly in order of modules on GST portal.
GST offline utility zip file after extraction gives one sample files in csv format. This is in "Section_wise_CSV_files" folder. Just copy this folder to your data folder anywhere in your computer.
Open each csv file you want to use. Remove sample data keeping 1st heading row intact. Enter your data for submission in 2nd row onwards and save file in same csv format before importing into "GST offline utility". You will not get error.