The number of molecules or ions from the following, which do not have odd number of electrons are ______.
(A) NO$$_2$$
(B) ICl$$_4^-$$
(C) BrF$$_3$$
(D) ClO$$_2$$
(E) NO$$_2^+$$
(F) NO

We need to find the number of molecules or ions that do not have an odd number of electrons.

We count the total electrons in each species:

(A) NO$$_2$$: N has 7 electrons, each O has 8 electrons. Total = 7 + 2(8) = 23 (odd).

(B) ICl$$_4^-$$: I has 53 electrons, each Cl has 17 electrons, plus 1 for the negative charge. Total = 53 + 4(17) + 1 = 122 (even). Not odd.

(C) BrF$$_3$$: Br has 35 electrons, each F has 9 electrons. Total = 35 + 3(9) = 62 (even). Not odd.

(D) ClO$$_2$$: Cl has 17 electrons, each O has 8 electrons. Total = 17 + 2(8) = 33 (odd).

(E) NO$$_2^+$$: N has 7 electrons, each O has 8 electrons, minus 1 for the positive charge. Total = 7 + 2(8) - 1 = 22 (even). Not odd.

(F) NO: N has 7 electrons, O has 8 electrons. Total = 15 (odd).

The species that do NOT have an odd number of electrons are: ICl$$_4^-$$, BrF$$_3$$, and NO$$_2^+$$.

The answer is $$\boxed{3}$$.