Synthesis of nano phased Er+3 doped (x) Li optimized Barium Strontium Sodium Niobates (BSNN), viz.,Ba1.6-(3x/2)Sr2.4Na1.4Li0.6ErxNb10O30 by co-precipitation method reported. XRD confirmed orthorhombic structure. Lattice parameter ‘b’ exhibited anomaly for x ≥ 0.8. Orthorhombic Cmm2 and Ccm21 symmetries predict Ferro or Piezo and Pyro response. (401) for x = 0.9; and (401) and (801) for x = 1 reflection and split infer Ccm21 symmetry and lower ordered Cmm2 structure along diad axis in [001] direction. Absence of additional (hol) reflections for h-even and l-odd are addressed. Crystallite size D(x) exhibited anomaly for x around 0.9. Particle size and Porosity P(x) by FESEM and Density ρ(x) inferred systematic growth of ferroelectric(FE) phase. Anomaly in D is attributed to distinct dopant characteristic nucleation. Cluster population of 10–20 nm size prevail over entire dopant range. Concurrent behavior of D and P with x is observed. Low frequency (100 KHz) Dielectric permittivity inferred shift of Curie temperature Tc for ambiance. Large permittivity (K) is observed for 0 ≤ x ≤ 0.2. Decrease of K with P confirms growth of nano phase from bulk morphology. Decrease in K with P infers morphology influence field response. Trends of K with x infers shift of Tc (x) with an anomaly for x equal to 0.9. influence of D and P analyzed. FE transition progressively gets diffused with increasing x or decrease in D (∼30–20 nm) and P (for 45–25 nm). Critical analysis of nano phased Er doped Li BSNNs reveals growth of localized stress contributing to excess free volume of grain boundaries. Incongruent behavior of Tc discussed. Trends of axial ratio (AR), dielectric permittivity and Tc are analyzed in comparison with the reports in other systems of relevance.