The V$SGA_TARGET_ADVICE view provides information that helps us in deciding optimal value for  SGA_TARGET.
MMON background process gather statistics about sga_target usage and update the V$SGA_TARGET_ADVICE view.

Check sga target advisory is enable?

SGA ADVISORY REPORT:

Now if we see the estimated stats for size factor 1.5(i.e with sga_size 153600M), then there is an decrease in est_phyiscal_read from 694123290 to 394123204 , But no significat change in est_db_time. So By considering the estimated improvement in physical read, we can take suggest to increases the sga_target from 102400M to 153600M.