How do you calculate and charge interest on outstanding accounts

depends on how often you pay off principle and how much dollars.
and how often you are charged interest.
fv=pv*(1+interest rate)^n n being the term of interest
so lets assume you pay zero off it and interest is calculated daily
fv=6300*(1+0.015/365)^365
interest = fv - pv
= 95.21 for one year without repayment
if you were to pay approx 25.15 a week you would pay this loan in 5 years time and pay approx $240 in total interest over five years
EXCLUDING future interest rate increases over the five years and excluding bank fees like account fees or account manage fee or setup a loan fee.
You could create a spreadsheet each day and calculate the interest as annual interest / 365 for the daily calculation
Then add the account fee onto the balance calc + any set up fee onto the start balance. by using =a$5 for the repayment on all rows as an example you can copy it down and the cell number will always be a$5
this way you can alter a5 and the repayment alters all the way down each week row.
or just download a template for excel
https://templates.office.com/en-us/Loan-amortization-schedule-TM10073881

its a lot of calculations you can try a per month system
loan givers do interest calculations daily

interest is added to your loan after you pay
so adds to the loan amount and increases the interest payment
every amount shown on the loan account has to be worked out

Interest Only

Contact your lender.

You may be able to set up online access to your account data through the lender's website. If that is available, it probably includes links for your account status, history and statements. The December statement likely shows interest paid during the year.

But how often is the interest applied, yearly or monthly? If yearly, then the last 3 months don't earn anything at the 29 mo point. So $27624.

If applied monthly the usual trick is to simply divide the yearly rate by 12 = 1.32% per mo. So after 29 mo, $30132

Assuming the 28k is put in as one lump sum each year and that the interest is compounded annually, then after 15 years I calculate $453,329
You can use the following online calculator to make adjustments, check my calculations, modify any factors, etc...
http://www.bankrate.com/calculators/savings/compound-savings-calculator-tool.aspx

$1,126.16

I want how i can calculate daily profit /loss calculation on investment

Recurring deposit interest is calculation may vary depends on compounding period. You have to invest an amount every month interest will be calculated for the current holding in your recurring deposit account. And every compounding period interest amount will be added into holdings or available balance. You can calculate the Recurring deposit using this recurring deposit calculator

Are you below the minimum balance?