I already served 2 fixed contracts for the same company

1. 1 year and 6 month extension
2. 3 years contract

So total 4 years and 6 months in total.....and the contract expiring in April...

What will happen to me...?

if i sign next 5 year contract with the same company....and I feel to change company after 1 year (completing totally more than 5 years with same company).....Shall i change company at that time ?

or will i not allowed to change company ????