Is 筙 commonly used in modern Chinese?

No, 筙 is an archaic variant form and is rarely used in modern writing. The standard character is 來.

What is the relationship between 筙 and 來?

筙 is a variant form of 來, sharing the same pronunciation (lái) and meaning 'to come'.

Primarily in historical or literary contexts, calligraphy, or when referencing classical texts where this variant appears.

筙Tone 2

lái ｜ 12 strokes ｜ radical:

Lái — an archaic or variant form of 來 (lái), meaning 'to come';

'to arrive';

'future'.

Lái — an archaic or variant form of'to arrive''future'.

Variant form of 來Ancient character for comingHistorical writing form

筙 is considered a variant or archaic form of the standard character 來.
Such variant forms often appear in historical documents, classical texts, or regional writings.
The character demonstrates the evolution of Chinese script over time.