To Akhmadi...
There are many brokers that can facilitate deposits under $100. In fact, almost every popular forex broker today already allows deposits under $100. What you need to pay attention to later is the type of account, because the minimum deposit range can vary depending on the trading account. At broker FBS for example, you can deposit $1 in a cent account, $5 in a micro account, a minimum of $100 in a standard account, and $500 in a zero spread account as well as unlimited.
So, when choosing a broker, just pay attention to the minimum deposit conditions in their trading accounts.
As a recommendation, you can listen to a complete review of forex brokers at List of Forex Broker Reviews.
thanks.