What am I doing wrong? I am trying to balance the equation:

NO3^-(aq)+Sn^2+(aq)-->Sn^4+(aq)+NO(g)

here are the coefficients I have. what is wrong with them?

2NO3^-(aq)+3Sn^2+(aq)+8OH-(aq)-->3Sn^4+(aq)+2NO(g)+4H2O(l)

What's wrong or what are the correct coefficients?

1. O doesn't balance--14 O on left; 6 on right.
2. Charge doesn't balance. 4- on left and 12+ on right.
I would balance it this way. I assume it is an acid solution.
8H^+ + 2NO3^- + 3Sn^+2 ==> 3Sn^+4 + 2NO + 4H2O

atoms:
1. 8 H on left and right.
2. 2 N on left and right.
3. 6 O on left and right.
4. 3 Sn on left and right.

charge:
12+ on left and right.

electron change:
N = +10 - +4 = +6
Sn = +6 - 12 = -6