<ul data-eligibleForWebStory="false">Vodafone Idea offers the cheapest validity plan in India for less than Rs 100 amid tariff hikes by other telcos.Priced at Rs 98, the plan includes 200MB data, unlimited voice calls, and 10 days of service validity.The plan aims to maintain Vi's average revenue per user (ARPU) and charges 50 paise per MB post data quota completion.Despite the short validity, the daily cost of using this plan is effectively Rs 9.8, making it a cost-effective option for users.