want to add more fish, what to add?

i would say you are very stocked there.

i'd leave adding any new fish. the cory needs to be in shoals of 6+ and so do the loaches. the tetras also perfer shoals.

how long has it been setup? what filters do you have ,plants??????

Bah, you should be able to add the fish you would like without much of a problem. Of course that depends entirely on how you have your tank set up. If it looks crowded it is crowded. Rams can be semi aggressive, but in my experience I have never had a problem mixing them with community fish. As for the shoals issue....personally, I wouldn't worry about that. I'm guessing the stress levels in your tank are pretty low, but if you don't have a lot of hiding spaces for the bottom dwellers then maybe add a few and you'll be fine. Rasboras should be fine as well. I like those little guys too!

Harlequin Rasboras are awesome little fish. They're even so active that my danios and tetras will join in and "school" with them, swimming along right in their little pack. I was a bit worried when I put them in my tank because they supposedly love more acidic water, but our water is around 7.6pH right out of the faucet, so getting a low pH for them is not easy. Still, they've done very well and are as healthy as can be.

I dunno, it looks like you're getting pretty full, especially in terms of water column fishes. You could probably get away with adding a few more cories, but I would be tempted to trade back the loach. Or vice versa, adding a couple loaches and returning the cory. They'll be much happier in a small group than alone.

One thing that the others have hinted at but not said outright is that your maintenance level is going to increase. I think that if you decide to build on what you've already got you're going to need high filtration (both bio and mech.) and water changes of 50% weekly at the very least. Twice weekly would be better.