So i can't remember if its a 3.5 E or not but in 5E can a ranger or a rouge that uses a bow an arrow or crossbow or the like get attack of opportunity on a person with in range or/and leaving melee with another party member?

2. can you get a sneak attack with a range attack weapon?

3. can you get an advantage with ranged weapon if an ally is in combat with another baddy?

1. No, you only get an Opportunity Attack when an enemy leaves *your melee range*, and that attack can only be a melee attack. So while holding a bow you cannot use it for an Opportunity Attack. You still can make an Unarmed Strike attack on anyone who moves out of your own 5' range.

2. Yes, you can get the sneak attack damage bonus with any attack which meets the requirements laid out in the class description; finesse or ranged weapon, and advantage on the attack or another active enemy of the target within 5'.

3. No, the other ally in combat with an enemy doesn't normally grant advantage (unless you are using flanking rules and those requirements are met). However, having an ally close to the target will let you use Sneak Attack (without advantage) as above. 

What Correon said.

What DxJxC said. 

Quote from Beardsinger >>

1. No, there are no opportunity attacks with a ranged weapon, only a melee weapon, or a spell if you have the warcaster feat.

2. Sneak attack with a ranged weapon is possible if you meet the required conditions  advantage on the attack, ally within 5' etc.

3. No, another ally cannot provide advantage for a ranged attack.

4. What's a rouge?

It's French for red.

Quote from Halfastbracegirdle >>

Quote from Beardsinger >>

1. No, there are no opportunity attacks with a ranged weapon, only a melee weapon, or a spell if you have the warcaster feat.

2. Sneak attack with a ranged weapon is possible if you meet the required conditions  advantage on the attack, ally within 5' etc.

3. No, another ally cannot provide advantage for a ranged attack.

4. What's a rouge?

It's French for red.

 I believe rogue was the intended word.

Flanking Rules, as described in the DMG, only apply to Melee attacks, so there's no way take advantage of that to get advantage. The only way an ally can provide you advantage without getting into like, class-specific abilities or feats, is through the Help action.

Quote from Beardsinger >>

1. No, there are no opportunity attacks with a ranged weapon, only a melee weapon, or a spell if you have the warcaster feat.

2. Sneak attack with a ranged weapon is possible if you meet the required conditions  advantage on the attack, ally within 5' etc.

3. No, another ally cannot provide advantage for a ranged attack.

4. What's a rouge?

 i.e. What Corren said ;-)

Quote from RegentCorreon >>

1. No, you only get an Opportunity Attack when an enemy leaves *your melee range*, and that attack can only be a melee attack. So while holding a bow you cannot use it for an Opportunity Attack.

I would just like to offer a slight correction. You can use ranged weapons for opportunity attacks - but you have to hit them with it as a melee weapon attack - which would make them improvised weapons and therefore 1d4 damage.
Otherwise - all correct.

Quote from Beardsinger >>

Quote from ArbitraryTTRPGer >>

Quote from Halfastbracegirdle >>

Quote from Beardsinger >>

1. No, there are no opportunity attacks with a ranged weapon, only a melee weapon, or a spell if you have the warcaster feat.

2. Sneak attack with a ranged weapon is possible if you meet the required conditions  advantage on the attack, ally within 5' etc.

3. No, another ally cannot provide advantage for a ranged attack.

4. What's a rouge?

It's French for red.

 I believe rogue was the intended word.

 I would never have guessed.

 Is ranged rouge the application of makeup from a distance... Maybe using something like:

https://media.giphy.com/media/l2JeaQtywqaPgyaQM/giphy-downsized.gif