4L of water and 2 max protein bars. Is it sufficient for a four hour ride?
I'll concentrate first on the carbs side, because the water depends on so many factors.

Gels are around 30% non-sugar carbs with the rest water, according to the SIS ones I have here.  They're actually a fairly heavy way to carry a small amount of carbs if you can get water along the way, but they're easy to consume while riding hard, and are meant to give a quick (but not too quick) energy boost.

Protein bars have more sugar (which you may or may not want) and a fair bit of protein, which is a poor energy source during a ride, and they're overpriced if you're using them as a source of carbs.

There are also energy bars.  One I have here is 67% carbs (about 1/2 of that sugar) and 4.9g protein.  It's based on oats and fruit.  These are probably better than protein snacks for use while riding.

Alternatives you may find easier to obtain are bananas and dried fruit.  Even bread-like carbs can be good  (second breakfast after an early start for me might be a wrap with a banana and chocolate spread in it, for example). It partly depends whether you can stop to eat or want to eat on the go (in France, for example, a bakery stop for fresh croissants is good).]  If you want to make something, flapjack is great (mainly oats, sugar, and  butter, add dried fruit/chocolate chips/crystallised ginger if you like).  Sweets have a place towards the end of a ride or for a specific effort like a big hill.  They're essentially flavoured sugar so your energy levels go up fast -- and down fast.  Jelly babies are popular in the UK, but they may not be available/suitable (gelatine tends to come from pork/beef).

It is perfectly possible to ride for that long without food (3.5 hour example in my case, after lunch), but you won't be as fast and you have to be careful. Make sure you're well fed to start with, carry snacks just in case, and don't even think about it if there are medical contra-indications.  I just chose to keep going without calories on the exploring/training ride I've linked, as I wanted to try running on empty.  I still got through a fair bit of water and the temperature wasn't much above freezing (I had to wait until after lunch for the ice to melt on the roads).

Water: on a hot ride I rely on topping up rather than carrying everything I think I'll need.  A recent hot ride got me through 6 litres in 12 hours, plus 1 before I started and another 2 when I got back.  That didn't feel like enough.  Bottled water seems pretty easy to buy in India, unless of course you're out in the countryside for the entire ride. I'd plan to pass somewhere with water available every couple of hours, at least until you've got a good idea of how much you get through.



Links are to arbitrary examples, including my own rides.  Products are ones I have lying around, usually because I picked them up cheap.