There's no such thing as "Service Tax" for a freelancer and the only tax you are supposed to be paying is Income Tax and again this all depends on the working relationship with your employer. Remember that although Upwork TOS tells you that you are an Independent Contractor, you may not be so with regards to the employment worker classification rules.
Usually Form 16/16A needs to be provided to you by Elance/Upwork/your employer at Upwork. If none of them provide you that, you can approach your area Assessing Officer and complain them about willfull failure on part of Elance/Upwork to pay taxes to Indian Government. TDS needs to be deducted as per one of the sections below :
1. 192 of Income Tax Act
2. 194J of Income Tax Act
For that purpose Elance/Upwork/your employer at Upwork needs to have a place of business in India and have a TAN/PAN number. In the absence of the same, you can report it to your Assessing Officer and file your returns accordingly.
There is no other form of tax applicable to Indian citizens.
Hope that helps.