It's misleading to say that Bhaskaracharya "developed caclulus". He worked on ideas that would later be important to the modern discipline of calculus, but so did many mathematicians before him.

Archimedes' heuristic accounts anticipate integral calculus, and he is the first known mathematician to use the infinitesimal. Eudoxus' method of exhaustion, found in Euclid's Elements, is another important predecessor to integration. The method of exhaustion was also discovered in China by Liu Hui. Zu Geng applied the more advanced method of indivisibles to find the volume of a sphere. But none of the mathematicians before Newton and Leibniz (Greek, Chinese, Indian, or Islamic) combined these ideas into a single, cohesive discipline.

Bhaskaracharya did not discover calculus, in the same sense that neither Archimedes or Liu Hui discover calculus. Victor Katz, a historian of mathematics, has this to say:

How close did Islamic and Indian scholars come to inventing the calculus? Islamic scholars nearly developed a general formula for finding integrals of polynomials by AD 1000, and evidently could find such a formula for any polynomial in which they were interested, but it appears they were not interested in any polynomial of degree higher than four, at least in any of the material which has so far come down to us. Indian scholars, on the other hand, were by 1600 able to use ibn al-Haytham's sum formula for arbitrary integral powers in calculating power seires for the functions in which they were interest. By the same time, they also knew how to calculate the differentials of these functions. So some of the basic ideas of calculus were known in Egypt and India many centuries Before Newton. It does not appear, however, that either Islamic or Indian mathematicians saw the necessity of connecting some of the disparate ideas that we include under the name calculus. They were apparently only specific cases in which these ideas were needed.

Ideas of Calculus in India and Islam by Victor Katz (1995)