For शर्बत, better term would be Pānaka (पानक), while रस translates to Juice. Pānaka is commonly used in Konkani.

In Himachal, Aam Panna is prepared (word is derived from Pānaka only)

Skanda Purana 2.7.3 advises charity of Pānaka in the month of Vaisakh & thats from where.. https://twitter.com/entropied/status/1322691160788316165

..tradition of प्याऊ or छबील during Nirjala Ekadashi and the entire month of Vaisakh originated

Some common types of Pānaka(s):

1. निम्बुफलपानक = Lemonade or Nimbu Paani
2. तक्रपानक = Chaas or Namkeen Lassi
3. काञ्जीका = probably elaborated version of modern day Kaanji
4. प्रपानक= Mango Panna or Himachali dish Mango Maani
5. आम्लीकाफलपानक = Some Tamarind Mocktail

6. . धान्यपानक = Some kind of coriander based mocktail/drink

Actually, in South India, sweet water is offered in Chaitra month during Ram Navami. Chaitra is the driest and warmest month
In North India, Jyestha is the warmest and driest month. So Chaitra to Vaisakha to Jyestha depending upon region, water is offered https://twitter.com/RajSharma1857/status/1322749822688845824

Bela pana (Odia: ବେଲ ପଣା) is a drink made from bael (Aegle marmelos) fruit pulp, during Chaitra and Boishakh, in Odisha, India. Pana Sankranti is celebrated where a sweet drink named Pana is prepared