Jobwork of hard annodizing

Proprietory Concern is running the hard anodizing unit Job work activities in bangalore and doing the job for their client which is situated in karnataka and tamilnadu also. so pl give opinion about vat deduction and service tax whether it will chargeable or not???

bcoz till now we are doing like we issue invoice without mentioned vat amount..

prinicipal give parts we do hard anodizing on it and after that we return that material back we use some chemical that we purchased by own

what are the legal requirement is there for job work plz suggest for vat,cst ,service tax purpose and excise also

and what if turnover exceed 150 lakhs in future

please help me out

waiting for positive reply

thanks and regard