Is it possible to travel by sea from India to Indonesia. Any advice will be welcome.
Yes, by container ship/freighter*.
There are many sites that offer exactly this service, either as booking agents or the line itself. Here are some examples:
However, India to Indonesia appears to have very infrequent or no scheduled service so you may have to research many options or combinations to find a routing that suits you.
*Of course, you can also charter a vessel.