Cst rate

Highest VAT rate in the state of seller will be applicable in case of interstate sale without C form. 

You have to pay tax at that rate as we pay if we sale it in the same state. i.e if the VAT rate is 5% then CST rate is also 5% with out C-Form. if the VAT rate is 14.5% then CST rate will also be 14.5%.

And what about Central Sales without form "C" @ 4.00%

Section 8(2)(b)

10% or VAT rate on such goods inside the selling dealer state, whichever is higher