A sed solution that selects a column by number:
echo 0 1 2 3 iv 5 6 | sed -E 's/^(\S+\s+){4}(\S+).*/\2/'or
echo 0 1 2 3 iv 5 6 | sed 's/^\(\S\+\s\+\)\{4\}\(\S\+\).*/\2/'replace the 4 (not the \2 at the end) with the column number you want, starting from zero.
Column delimiters are any combination of any number of tabs and spaces.
-r flag uses extended regex syntax which is more concise.