A thorough comprehensive microstructure analysis of poly(dimethylsiloxane-co-hydromethylsiloxane) copolymers (PDMS-co-PHMS) was achieved using high resolution two-dimensional NMR ((29)Si/(1)H) techniques viz. heteronuclear multiple bond coherence (HMBC) and total correlation spectroscopy (TOCSY) in conjunction with 1D (29)Si and (1)H NMR srctroscopy. A rigorous analysis of the splitting patterns along (29)Si NMR axes of hydromethylsiloxane, [-OSi(H)Me-]/"D(H)" units and dimethylsiloxane, [-OSi(Me)(2)-]/"D"units in PDMS-co-PI-IMS revealed sensitivity of their chemical shifts to variation in copolymer composition. Interestingly, (1)H NMR signals of hydromethylsiloxane, [-OSi(H)Me-] units showed an additional sensitivity to tacticity (meso, racemic) effects. With aid of 2D HMBC ((29)Si/(/1)H) NMR spectra, we could resolve unambiguously the highly complex and overlapped -Si-CH(3) region in (1)H NMR spectrum into the respective compositionally and configurationally sensitive D/D(H) triads. Further, the reactivity trend of Si-H groups was studied by hydrosilylation reaction of these copolymers (PDMS-co-PIMS) with model molecules like alpha-methylstyrene and I-octene. An intriguing trend toward preference for racemic (r) orientation of Si-H on PDMS-co-PHMS backbone during hydrosilylation reactions resulting in syndiotactically enriched products was observed. This observation signifies a crucial fact of possible scientific interest that the Si-H dyads with the racemic configurations were more available for complexation with Pt catalyst during hydrosilylation than the meso dyads. The authors attribute these not-so-obvious experimental observations to the role of conformation of the polymeric chains. The interpretation of these peculiar findings and the reactivity patterns observed has been documented in this article.