Thanks for posting your question @Mahesh Babu Gadhamsetty.
I've looked into this and determined you haven't met all the requirements just yet. In order to get to the $25k sponsorship, you must spend at least half of your initial $5k credits in addition to the other requirements. You can find more details under How do I get an Azure credit offer of $25,000?.
Once you've spent $2500, you should get promoted into the next level.