Well below I have given you the good books to prepare for the Indian Forest Services IFS exam so you can have a look

UPSC-IFS (Paper I & II) Main Examination Guide: A Complete Book for Pa
UPSC-IFS (Paper I & II) Main Examination Guide:
306.00



Upsc: Civil Services & Indian Forest Service (common Preliminary: Paper-i) Exam Guide
Upsc: Civil Services & Indian Forest Service ...
889.00

Upsc Civil Services Indian Polity Exam Paperback English Latest Edition
Upsc Civil Services Indian Polity Exam Paperback ...
249.00

IFS List of optional subjects

(i) Agriculture

(ii.) Agricultural Engineering

(iii) Animal Husbandry & Veterinary Science

(iv) Botany

(v) Chemistry

(vi) Chemical Engineering

(vii) Civil Engineering

(viii) Forestry

(ix) Geology

(x) Mathematics

(xi) Mechanical Engineering

(xii) Physics

(xiii) Statistics

(xiv) Zoology