Hey Sagar, Book your trek either with Trek The Himalayas or India Hikes ( Best trek companies in India). You will go in a group of max 15 trekkers. These are little expensive than other trekking companies but services are best. Hope this would help you.
There are many groups like TTH, Bikhat Adventure, Crazy Peaks, etc that are organizing trek to Kedarnath. You can join them. If you have your own group of 8 to 10 people then you can contact locals they will also help you to do the trek.
Hi Sagar, I'm sending below the link to Kedarkanth Trek package. You can click on it and find all the details about it. If you want to book this or get it customised, simply put your details in the form and someone from the package providers will get in touch with you.
https://www.tripoto.com/tour-packages/trek-to-kedarkantha
There are many companies which organise treks. Like India hikes, Trek the Himalayas, binary adventures and many more. Almost every company organises the kedarkantha Trek. You can just visit their website and can check for yourself.