When an exchange creates an Index, what does it really mean? is it necessarily available for "retail investors"?

I can buy CSE stocks on my iTrade account, but I can't find any such indexes.

Is there a way to find a related Index Fund?

An index is just a mathematical formula (F) that turns a set (S) of input numbers (usually the prices of individual stocks) into a single output number (I).

Anybody can create an index. You can vary S and F to arrive at any output number you want.

Sometimes someone will create an index `ABC` whose S and F are deemed by other people to be "useful" for the purpose of representing the overall state of a certain segment of a financial market.

If enough other people agree about `ABC`'s usefulness over a long enough period of time, eventually financial services company `XYZ` might create a financial product `ABCXY` to do any of the following:

1. use the money from Alice's purchase of `ABCXY` to buy a corresponding amount (according to F) of each stock in S. When Alice sells `ABCXY`, sell a corresponding amount of each underlying stock to give Alice her money back.

2. use the money from Bob's purchase of `ABCXY` to make investments whose overall value (hopefully) tracks that of I over time. The investments may or may not have anything to do with the stocks in S.

3. use the money from Charlie's purchase of `ABCXY` to make investments whose overall value (hopefully) outperforms that of I over time. The investments may or may not have anything to do with the stocks in S; in this case `XYZ` must do something different from the index if they want to outperform it.

4. return income equal to some multiple of the income that would be generated if an investor held all the stocks in S. That multiple can even be negative. Again, the underlying investments may or may not have anything to do with the stocks in S.

5. futures or options or other derivatives on any of the above

There's no telling how popular or "useful" an index needs to be before `XYZ` company decides to create a financial product based on it. And, as illustrated above, even if `XYZ` does create such a financial product, it might not be exactly (or even remotely) equivalent to holding all the stocks in S.

So, no, just because an index exists does not mean that a corresponding financial product exists.

As for `CSE`, they show their current S and F on their website. If you want to invest according to their index, you can buy those symbols in those fractions. But note that their S and F may change on a regular basis, and it's not immediately obvious how frequently they update that webpage. So 3 months from now you might find that your investments have deviated from theirs.