Yes, you can.
If you have purchased any of the J'JO subscriptions, you will be able to create your own index or portfolio. After creating a portfolio/index, you can invest in any number of portfolios or indices simultaneously.
Example:
Let's say you have 5000 USDT in your exchange account. You invested 3000 USDT in the system J'JO index, and the remaining funds can be used at your discretion, traded on your exchange, or invested in any of the proposed J'JO ready-made indexes or portfolios created by you.
The number of possible portfolios on one exchange is not limited.