I actually heard, that there has been a regular passenger ship going between Chennai and Penang as recently as the 80´s. But then it caught fire, or sank, or caught fire, and sank...
In case the guidebooks are correct, there are still regular services going between the Andaman&Nicobar Islands and mainland India, so maybe its possible, if you can find some boat to take you there from Thailand... even that is a long way, but if you´ve got time to work it out & money to arrange it, I guess anything might be possible in Asia!
But do take into account that handling the immigration & especially customs for your bike could be a lot more challenging, if entering India that way (clearing the vehicle into India often is, even when entering the ´regular´ way!) so all in all I would not recommend doing that, there´s no guarantee you can enter that way.
Getting your vehicle to move between India and Thailand has been a royal pain-in-the-___ for decades, and will probably stay that way for the foreseeable future. Freighting it by sea or by air, and flying yourself is possible however.