Summing up the day at 186 without loss, India enjoyed another dominant batting display with both openers converting their overnight starts into centuries.
Raichandani remained unbeaten on 196 off 306 balls, smashing 21 fours and three sixes. He was battling with Kush Patel, who was unbeaten in three at the end of the game.
Sagar Virk also scored the century
Raichandani found excellent support from fellow opener Sagar Virk, who scored a patient 134 off 312 deliveries.
The opening pair laid a solid platform for India before Virk departed after his century.
India route from 46 runs
At stumps, India U-19 were 378/3, after Sri Lanka U-19’s first innings of 46 runs.
The hosts had earlier posted 424/9 declared, thanks to a brilliant double century from Senuja Wekunagoda.
Match will be played in Galle
The Youth Test is being played at the Galle International Stadium, the venue that will also host the first Test between the senior teams of India and Sri Lanka next month.