Tempted to get the same bat as Sachin Tendulkar or any other top international player from the sub-continent?

Beware - Hero Honda is a motor manfacturer, they do not make bats for professionals. They sponsor international cricketers, who use their red and white stickers on high quality bats (most notably, the SS, SG and BAS brands) - but Hero Honda do not make pro bats, just cheap recreational ones because of an ICC ruling which states that an international sponsor must manufacture bats if their name goes on a bat. So Hero Honda bought a small bat company in India. Be careful with this as virtually all of the Hero Honda bats on Ebay are not the ones used by international players but cheap rubbish or even fakes (more on this here).
Reebok do make bats but MS Dhoni does not use a Reebok bat, though Reebok pay him very well to endorse their products. Dhoni uses a very heavy SS but was also recently pictured with an SG... Same with Yuvraj Singh, who uses an SS bat.

And as for Britannia, they are a biscuit company and also do not manufacture pro bats. If you have a Britannia bat, it's probably an el cheapo.

A possible exception is MRF (tyre manufacturing company which owns a small bat subsidiary) - this brand of bat is sold in some Ebay stores as well as in private auctions. Personally, I would not buy one as some of them are made of Kashmir Willow (see my other guide on willow type and grades here). One of the selling points of the MRF range is that they are used by the likes of Brian Lara and Tendulkar - but Tendulkar often uses MRF stickers on an SS bat.
Also remember, some of these listings state that the bats are made of Grade A willow - there is no such thing as "Grade A" willow. There is only grade 1 through to grade 5  - with grade 1 being the best and running all the way through to the lowest quality grade 5... "Grade A" is just something some sellers have made up to confuse people into thinking it is somehow superior. Bat-makers do not recognise this grading and neither should you.

A thought - there is nothing wrong with getting one of these "sponsored" bats (even if it is made of Kashmir Willow and is of an inferior grade) if you wish to play social cricket in the park - but be careful if it is for serious cricket at club or higher level. Don't pay top money for what is essentially just a novelty item.

Sorry to burst your bubble, but did you know that the majority of the South African national team uses bats made by Bellingham and Smith, a small, privately run entity? The stickers you see on the players' bats do not matter - it's the quality of the willow. Most international players change the livery (stickers) every season to match the branding of their big sponsors but the bats are privately manufactured! Same story for the Aussies - many of their bats are made by Laver & Wood and Bradbury. Most of the Indian team use SS and SG bats while the Pakistanis are known to favour CA and AS.
Please read my other related guides and rate them if they were helpful.