Let $(E,M,p)$ be a smooth n dimensional vector bundle. Then $(TE,TM,Dp)$ is a 2n dimensional vector bundle. We restrict this bundle to $M\subset TM$. We denote this restricted bundle by $F$, as a 2n bundle over $M$. In this situation we say that $E$ is the integral of $F$ and write $E=\int F$. In this question we search for a converse statement:
Question:
Assume that $F$ is a 2n dimensional smooth bundle over a manifold $M$. Is there a smooth n-bundle $E$ over $M$ such that $E=\int F$? What obstructions would appear? Assume that $E_{1}$ and $E_{2}$ are two solutions of $E=\int F$. What can be said about the difference $E_{1}-E_{2}$ as an element of K-theory?