Must I serve the full notice period?

As per your employment contract. You can pay salary in lieu of notice period to leave early. Employer cannot force you to work beyond what is reasonable.

The notice period is governed by your employment contract. Most contracts allow you to either serve the full notice period or pay salary in lieu of notice to leave early. The employer cannot force you to work if you pay the notice period buyout amount. Standard notice periods range from 1 to 3 months depending on the industry and role. Some key points: the employer cannot extend the notice period beyond what is specified in the contract; garden leave (paid leave during notice period) must be with your consent; the employer must relieve you on the last day of notice period; unreasonable notice periods (like 6 months) can be challenged as being in restraint of trade under the Indian Contract Act.

• Indian Contract Act — Section 27 (Restraint of trade)
• Employment agreement terms
• Industrial Disputes Act