Hi, You shouldn't have joined another company without being properly relieved by your previous company. Now that they have terminated your services, you are free to join any company. However, you will not be able to provide an experience certificate. Also, in case of any background verification by your new employer, your old company will only provide negative feedback. Since your old employer has blacklisted you, they will not consider you for rehire.
This situation does not mark the end of your career.
You can try to join a company that does not insist on experience or a relieving order.
Learn from the mistake you made and ensure you do not repeat it at any cost.
Wishing you all the best!