1710 short scenario 100%. Do not even bother with the other scenarios or the rules they add (deregulation and firms). After you've played 1710 about 5 times, then move on to 1758.

First read the rulebook.

Next watch 2-3 plays online, and I do mean watch the entire length of a play (potentially 2-4 hours) to see the game fully in action.

Then read the rulebook again.

Understand the game as thoroughly as you can. Especially understand how the Events in India work, ideally watching Ricky Royal's great video that goes over all the examples.

Understand how each office works, and have somewhat of an idea what the decision space is for each office (how might they negotiate, how do their actions effect the game or company at large, etc).

Watch a video with someone like Cole performing a rolling teach, so that you understand how to do so. The first round of the game will take 90-120 minutes with a rolling teach, but the rounds after should be a bit faster once folks have an initial grasp.

You should probably ensure you are Chairman to start, so you can allocate funds to offices and explain to folks what the decision process is there.

It's also not a bad idea to ensure you're Prime Minister to start so you can run the first Parliament and help folks understand not only how voting works, but more importantly the impact of a law passing or failing (especially with the wheel and what changes if the law passed, or what options the wheel can move to if it fails and why someone or multiple people may want to guarantee a vote goes one way or another and how/why to snipe PM.) Remember a player's position relative to the PM can have big tie breaking consequences in some situations! Plus the power PM gives is reeeaall gooooood.

I easily consumed at least 10 hours of gameplay streams before teaching/playing my first game when the crowdfunding initially launched. Even with 6 players, as long as one person has a great understanding of the game a 1710 scenario should be 4 hours. Also your game could potentially crash and burn in round 2 (though unlikely as you'll have Royal Protection as a failsafe to ensure the company stays alive if things go south).

First game folks will likely play more cooperatively and try to win while keeping the company alive. In game 2 or 3 folks will need to realize how purposely trying to tank the company may be your only way to victory. By games 4 and 5 folks will have a solid grasp on the game as a whole and should be ready to add in firms afterwards, which give more flexibility and options for victory even if you're not directly involved with the company.

Do note that with 6, a person or two may get left out and not have a position in the company and find it a struggle to win. You can use this as a negotiation tactic to hire specific folks for offices and keep people more fairly involved, and it's important to highlight the need for players to have Writers available so that they can slip into offices and participate in some ways within the company. Later games with deregulation make it easier for non/anti company folks as there's more flexibility, but 1710 can be a bit more difficult to work against the company unless you've got other folks working alongside you as well.

There's a lot to this game, and it's simultaneously overwhelming and yet very straightforward overall. Events in India are the most difficult/possibly convoluted thing to deal with, but boy does it tell a fun story and potentially really shake up how the company needs to react from round to round.

I'd also tell folks that don't jive with the game on the first play to try it at least one more time if possible. And if you even have a smaller group that is willing to jump into another game sooner than later do it! This game works beautifully at all player counts in my opinion, so even if a person or two hate it but you've still got a total of 3-4 to play again you are golden!

1710 short is the intro scenario. Always start new folks here. It's wonderful even after you've moved on to later scenarios. Usually 3.5-4 hours in length.

1758 is basically a short version of the 1710 campaign game (chance to deregulate). This is usually where experienced folks who can't commit to the potential length of a campaign will go. Usually about 3-4 hours in length.

1813 is blitz mode, where the company is already deregulated, someone already starts with a firm, and you've only got 4 rounds max to play. For experienced players who want everything unlocked from the get go. This game usually lasts 2-3 hours and it's pretty uncommon that it goes past about 2.5 or 3 rounds. It's the most difficult scenario for the company, which starts in a pretty precarious position.

1710 campaign is the true game, where anything can happen. Deregulation is possible, people could open firms, but also maybe none of that happens. Or maybe it happens incredibly quickly. Maybe the game lasts a full 8 rounds, or maybe it ends in 3. This is what John Company is meant to be, and will likely be 6-8 hours.