Sir/ madam, is it posssible to completely depned on ncert math textbook for grade 10 ? if not , which book should i refer to ? is there any chance for direct questions and previous board paper questions to repeat ?

ya definately question may repeat . Also you should not completly relay on NCERT use ohter practice book to practice more and more . The more you work on it more tthe concepts will get clear and your problem solving skills will improve

So, solve previous year questions all
Solve NCERT(full) . Also revise
And Practice from good books(eg pradeep in maths)