Hi Sandeep,
It would be irresponsible from my side to advise you on when to take your exam. Every situation is unique. It should be your decision depending on your personal circumstances. I suggest you read through our forums and see what people say about the exam. Now you have lessons learned available from the people who already took their exam which is still based on the current exam outline. Having lessons learned from the current exam is beneficial for your preparation. After the exam changes, it's obvious that it will take some time until the number of lessons learned posted about the new exam will be the same (or similar) to the number of lessons learned posted for the current exam. So if you are not in a rush or you don't have enough time to get ready for the exam before it changes, you can wait until the exam changes. If you want to take advantage of the current lessons learned and you think you will be able to get ready for the exam before it changes, you may consider to take it now. Again, it's a highly subjective decision which only you can make for yourself.
Hope it helps.
Regards,
Stan Po, MBA, PMP, PMI-ACP, CSM, CIPP
Product and Program Manager
OSP International LLC