how to find electric field inside the sphere of charges..?

If the spis hollow then electric field

will be zero inside it using Gauss Law.

If the sphere is solid (let the uniform charge density of the sphere be p)

then using Gauss Law,

p.(4/3)*pi*r^3/e = E.4*pi*r^2 (E will be radially outward from symmetry,

e is the absolute permittivity of free space)

=> E = p*r/3*e