Question: * Holding A♣ 6⋄
* Flop K♣ 9♣ 6♣
* BB goes all in on Turn.

If I flop a club on Turn or River, pot is mine for sure. I call his all in, miss the flush, BB has two clubs and takes it. Should i have called his him?

Answer: 
As @Chris said, this greatly depends on your stack. In addition, you don't say if you're playing *cash* or a *tournament*.

At the moment you only have a `6` pair as a made hand. This may be sufficient or may not depending on your stacks.

If you are playing a *tournament* and you're desperately low, say having `10-15` blinds, then shoving here is `never` a bad play.

You have 9 outs for the `nut` flush, plus 5 more for `2-pair+`. Therefore you have around 14 outs, which means `above 50%` to the showdown.

These kinds of combo draws (flush draw + pair, open ended straight draw + flush draw etc.) are pretty much the `nuts` when you're very low in stack. You're often ahead even against `TPTK (top-pair top-kicker)` like a `AKo` here with these monster draws (in this example, having the ace is making you a little underdog but you get the point).

However, if you're deep stacked, you're not desperate. You need to play the hand by paying attention to `pot odds`. Since you have `14 outs`, you have around `28%` per street to improve (say it's `30%`). A `~30%` pot odds is often created by someone betting the `full pot` `(33%)`, so if someone bets this or lower and have a deep stack, you know it's OK to call.

In your case, calling his all-in, you're not mentioning the `pot odds`.
The pot odds are calculated like this:

```
pot_odds = amount_to_call / (current_pot_size + amount_to_call)

```

If you end up with something below `~0.3` (30%), you know it's OK to call.

There's no standard way for playing this without additional input as @Chris said. For example, if someone have a deep stack and a call it's going to cripple him, it's probably best to fold as a `marginal 50%+ equity` is not quite much when have a deep stack, but it's awfully plenty when you're desperate.
You can think about the range of cards the villain could have that would make sense for him to push with, I'm assuming his all in is around pot size or less, overbets probably narrow villains range further:

Big drawing hands: 78 off, T8 with a club, 57 with a club, JQ with a club

Two pair hands: K9, 96s

Top pair: AK, KQ, KJ, AA

Sets: KK, 99, 66

Made flush hands: I've included all suited gap and double gap club connectors.

Air hands: How often will villain try and represent a flush/big draw?

Now you can take a lot of these out of his range if he's short stacked or a generally tight pre-flop player, and with information about how pre-flop went (was he given great odds to play preflop?)

Even with all of this range and without any bluffs, you are a favourite according to pokerstove. I suggest you play around with opponents hand ranges in pokerstove when analysing hands, and see how your holding plays against this.