gistfile1.txt

while IFS= read -r line; do
    # Check if the line contains a tab
    if [[ "$line" == *$'\t'* ]]; then
        # Split the line by tabs into an array
        IFS=$'\t' read -r -a cols <<< "$line"
        # Only process if at least 4 columns exist
        if [[ ${#cols[@]} -ge 4 ]]; then
            # Grab column 4
            col4="${cols[3]}"
            # Do the replacements using perl
            col5=$(perl -pe 's/-private|-tooling|-v[0-9]+(secondary)?//g' <<< "$col4")
            # Output original columns plus new column 5
            printf "%s\t%s\n" "$line" "$col5"
        else
            echo "$line"
        fi
    else
        echo "$line"
    fi
done < yourfile.tsv