Spelling Mistake in my marksheet

No problem. This is not going to create any problem. The important details on your marks sheet are your name and the marks you obtained and class. They are all correct. Only a spelling mistake in mentioning the class. If they mention a second class instead of first class, it will be a problem.
You will get your provisional certificate and then you will get your original certificate and they will mention the class in that and that will be the authentic document for the class obtained. So you need not worry.

Generally the mistakes in name, father's name, age etc are considered of serious nature and are to be rectified by requesting them to issue a corrected certificate. They create problem at the time of document verification when you go for counselling sessions or interviews. Other typo mistakes as you have mentioned in your case are of minor nature and you need not to bother about them.

Is this the final mark sheet issued by them? If so you can also just send them a plain application asking them to correct this typo mistake in their records and issue a corrected mark sheet. Attach a copy of your present mark sheet with it for reference. Hopefully they will send you the corrected copy of the same. However, as I have already explained, it is a mistake of minor nature and can be ignored.

The spelling mistake in the word 'first' is of minor nature and very well suggestive of the word itself. Such mistakes are very common and known as typographical errors and generally accepted in the documents. It is only when there are bigger mistakes like 'second' or 'third' or 'pass' in place of 'first' that they create problem in their acceptance if the candidate claims otherwise. Anyway in this case I do not see that there will be any problem during the verification process of the academic documents.

You need not worry about the mistake that happened in your mark sheet. Majorly your name, surname or fathers name was mistaken then that would be a serious issue down the line. Moreover, no one will see the spelling mistakes during your interview, They concern about the percentage got in your academic. Your mistake is very minor. In place of "First " if they would have written "Second" then that would be a problem for you but not the interview panel of any X private employer.

If you still have a doubt in your mind you may meet your class teacher or headmaster of the school and discuss your concern. As per my view, this is a very minor/negligible issue.

In the first place I am curious to know about what led to that mistake when this is already a computer generated copy, which I hope so that this should have been the case. Going ahead, pl. check this with your colleagues as well & escalate this with the Head-Of-Department (HOD) or the Principal whosoever the concern person is. Although this mistake is negotiable for the future transactions or uses but it's good to get this rectified on time. I suggest you to pl. keep the copy of this application with you too for reference references till the time you get the rectified copy with you.

In addition, there is no need for too much worry onto this account as this is just the negligible one & the concern authority from you college or the University can put on another's record when required by a third party but at the same time you must be checked with the other details on the mark sheet as the numbers of other error can make you uncomfortable later on.

Lastly, I would appreciate yours concern for raising with such small errors with a request to pl. go through with the experts advise & get this rectified even though being negligible.

Even I am surprised to read your query because this is the computerised format how can there be a mistake of "first" in the mark sheet. Although it's not a very major issue still it should be rectified. You won't get any problem with getting a job for this problem.

You should get it rectified by contacting the education board from where you got the certificate. You may contact them online and should write about your issue and follow what they say to do. In a few days, this can be corrected but you need to contact them first.

It is common to have some mistakes while entering name/s in certificates and it is our duty to Chek while receiving. This may be due to the steps of both sides. While furnishing our name in application we should take utmost care as a)with or without space b) when we follow some numerology adjustments.
To correct this we have to approach the concerned authority IN PERSON with relevant documents without delay.