In 'sanskritik' (cultural), the suffix is—

The word 'sanskritik' is formed by adding the suffix 'ik' to 'sanskriti' (culture). The 'ik' suffix is a common Sanskrit-derived suffix used to form adjectives from nouns in Hindi (similar to 'sanskriti + ik = sanskritik', 'samaj + ik = samajik', 'dharma + ik = dharmik'). This is a standard pratyay (suffix) in Hindi grammar.